11 - 14 February 2020, Quebec, Canada
5th International Congress on Soldier’s Physical Performance (ICSPP)
Impacts of climate change on national security and Warfighters’ health.
In his symposium talk, Dr. Flouris analysed the relevance of climate change on the preparation of modern armed forces for the conduct of (i) combat and (ii) non-combat operations. For combat operations, climate change increases the triggers for conflict (e.g., through land-use changes and resource scarcity) and alters the environments in which conflict takes place, as extreme events (particularly heatwaves and droughts) become more frequent. In particular, the majority of combat operations during the past decades took place in exceedingly hot and cold environments. For non-combat operations, climate change raises the likelihood of deployment in response to a developing situation by increasing the frequency and intensity of natural disasters and people movements through borders. The latter has become a growing crisis which is projected to intensify during the 21st century and armed forces will need to deploy more and more often to support civil authorities in response to migration crises. In conclusion, Dr. Flouris highlighted that climate change and global warming lead to global instability through increased natural disasters, intensified competition for ever-diminishing food and water resources, amplified socio-economically motivated armed conflicts, and difficulty controlling national borders. As such, armed forces must adapt warfighter preparation as well as current and future operations (both combat and non-combat) to the direct and indirect impacts of climate change and the associated risks to national security.
20 - 21 November 2019, Singapore
Inaugural First Responder Safety & Performance Symposium (FRSPS)
Emergency Response Operations under Climate Change and Extreme Environments
In his talk, Dr. Flouris discussed how climate change raises the likelihood of first responders’ deployment – particularly in hot environment – by increasing the frequency and intensity of natural disasters and people’s movements through borders. In the second part of his talk, Dr. Flouris focused on the extreme conditions under which first responders and other similar occupations typically operate in, caused by the environment, the psychophysical stress, and the need to wear protective clothing. Taken together, the two parts of this talk discussed the relevance of climate change and extreme heat environments on the safety and effectiveness of emergency response operations.
6 - 9 November 2019, CSEP 2019, Kelowna, Canada
Inter-individual factors and screening criteria for exercise-induced heat strain.
Invited talk in the Symposium titled “Operation Heat Shield Canada – Protecting Human Health during physical activity on a Warming Planet.
In his talk, Dr. Flouris described how climate‐driven increases in heat exposure as well as societal changes such as population aging generate important public health risks, as specific population groups have increased susceptibility to heat stress. In his presentation, he described simple and practical group‐specific screening criteria for susceptibility to heat stress during work and leisure activities in hot environments that have been recently developed and validated during large studies in laboratory as well as occupational settings.
5 November 2019, Athens, Greece
Symposium organized by the European Trade Union Confederation Project “Involving Trade Unions into adaptation policy”
Climate change, work conditions and occupational health.
In his talk, Dr. Flouris described the global state-of-the-art regarding the occupational heat stress impacts in terms of health and productivity. Also, he gave recommendations on how employees and employers should move forward and the existing evidence-based recommendations regarding personalized warning systems, work-rest ratios, clothing, mechanization, hydration, as well as vulnerable populations.
8 October 2019, Athens, Greece
Invited talk at the roundtable "Occupational heat stress and strain", organized by the Greek
Meteorological Service and the Greek Ministry of Labour.
Evaluation and adaptation to the risks of occupational heat stress and strain.
In his talk, Dr. Flouris described the best available evidence on how to reduce the effects of heat stress on the health and productivity of workers in strategic industries of Europe. He also described the case studies as well as the larger investigations carried out by HEAT-SHIELD members across Europe to identify ways to support workers, employers, and stakeholders in mitigating occupational heat stress.
7 - 12 July 2019, Amsterdam, Netherland
15th International Conference on Environmental Ergonomics
Andreas Flouris, Leonidas Ioannou, Sean Notley, Glen Kenny and Lars Nybo
Inter-individual factors and screening criteria for occupational heat strain
Introduction: Climate-driven increases in heat exposure as well as societal changes such as population aging generate important public health risks, as specific population groups have increased susceptibility to heat stress. Most heat-induced deaths are of cardiovascular origin, yet there is no increase of cardiovascular admissions during heatwaves. This has led to the conclusion that deaths from cardiovascular disease during heatwaves occur rapidly before the patient is admitted to a hospital and that the first hours of heat exposure have a major impact on cardiovascular mortality. To address this vital public health issue, it is vital to develop criteria to identify and, ultimately, protect individuals who are more susceptible to heat stress, particularly those who are still part of the workforce and, thus, are physically active during periods of increased heat. This presentation will describe simple and practical sex-specific screening criteria for detecting susceptibility to heat stress during work and leisure activities in hot environments. The screening criteria have been developed from simple information derived from age, anthropometry, and cardiorespiratory fitness and have been recently validated during large studies in laboratory as well as occupational settings.
This work has been supported by European Union's Horizon 2020 research and innovation programme under the project ‘Heat-Shield’ (grant agreement no. 668786).
Conclusions: The developed criteria are based on robust risk factors that have been rigorously studied during the past decades and can be used as simple and effective means for detecting the vast majority of people who are less able to work or play in hot environments owing to their reduced capacity to dissipate heat. Therefore, the proposed criteria can play an important role in preventing and mitigating the public health risks caused by increased ambient temperatures.
Leonidas Ioannou, Sean Notley, Glen Kenny, Lars Nybo and Andreas Flouris
How well do thermal Indices Quantify the Magnitude of Occupational Heat Strain?
Introduction: Hundreds of thermal indices have been introduced aiming to quantify the magnitude of heat stress/strain, reduce heat related illness, and enhance productivity. However, the exact number of thermal indices which are depended to at least one out of the four environmental factors (air temperature, humidity, radiant heat, and air velocity) remains unknown. Moreover, it is unclear which of these thermal indices actually reflect heat strain and physiological function in occupational settings. Therefore, the purpose of this study was to identify all the thermal indices developed during the last century, by conducting a systematic review and meta-analysis of the literature.
Methods: Following PRISMA guidelines, we searched six databases for relevant studies. No language or any other study design limits were applied. Furthermore, we supplemented the electronic database searches with manual searches for published studies in international trial registers, ISO standards, and websites of international agencies (e.g., World Health Organization and World Meteorological Organization).
Funding was provided by ‘Heat-Shield’, European Union's Horizon 2020 research and innovation programme under the Grant agreement no. 668786.
Results: Of 556 records identified through our systematic search, 104 studies written in 9 different languages met the eligibility criteria for inclusion in the study. The analyzed studies included 172 thermal indices. The first index identified was developed in 1915 while the last one in 2016. Interestingly, a very strong relationship was found between the year of development and the number of thermal indices developed (r=0.97, p<0.01), indicating that more indices should be expected in the future. Finally, a computer software has been developed to simplify the calculation of the identified thermal indices.
Conclusions: Based on the systematic review, this presentation will describe the relationship between thermal indices and the thermophysiological responses of workers who work in different industrial sectors around the world.
Leonidas Ioannou, Lydia Tsoutsoubi, Konstantinos Mantzios, Giorgos Gkikas, Gerasimos Agaliotis, Constantinos Dallas, Lars Nybo and Andreas Flouris.
Thermophysiological Responses and Heat-Induced Labour Loss in Agriculture
Introduction: Occupational heat stress is detrimental for human performance leading to significant labour loss. However, the magnitude of this problem remains unclear even in industries such as agriculture which are depended on manual labour conducted outdoors. Therefore, the aim of our study was to quantify the magnitude of heat-induced labour loss and examine the thermophysiological responses of agriculture workers during different seasons.
Methods: During the last three years, we evaluated >1000 work hours via time-motion analysis on a second-by-second basis collected from 165 workers (age: 41.9±13.0 years; BMI: 25.8±4.8 kg/m2) while performing different agriculture jobs. Physiological data (core temperature, skin temperature, and heart rate) were collected from 22 individuals. Environmental data were recorded throughout the work shift using a portable weather station.
The study has received funding from the European Union's Horizon 2020 research and innovation programme under the Grant agreement no. 668786.
Results: Very strong relationships were identified between thermophysiological responses (core temperature: r=0.96; skin temperature: r=0.99; heart rate: r=0.93), labor loss (r=0.94) and air temperature (all p<0.001). Precisely, labour loss escalates from 3.9%, during low occupational heat stress (11-18°C), to 14.2% during high occupational heat stress (27-34°C), increasing by 0.65% for every 1°C increase in workplace temperature (R2=0.87, p<0.001). On the other hand, we found a negative relationship between metabolic rate (r=-0.33) and air temperature (p<0.001).
Conclusions: Occupational heat stress affects the human thermophysiological responses leading to impaired capacity to perform work.
22-24 May 2019, Varsaw, Poland
1st European Biometeorologist Regional Meeting
Biometeorological forecast chain to develop thermal comfort/discomfort maps for Italy according to the UTCI
Messeri A, Morabito M, Crisci A, Messeri G, Betti G, Vallorani R, Gozzini B, Orlandini S, 2019
Climate change is leading to an increase in the frequency and severity of hazard events such as heat waves and cold spells across the globe and particularly in Europe. These changes have a direct effect on human health and in particular on the vulnerable people such as the elderly, children, workers or people suffering from chronic diseases. Despite this, nowadays weather forecast services provide little information about the effects of this particular class of hazards and only few specific weather service based on biometeorological forecast are actually available. The reliability of the Universal Thermal Climate Index (UTCI) as a heat-related health risk indicator in Europe is already widely demonstrated in recent literature. The aim of the present study is to illustrate the reliability of a comprehensive biometeorological forecast service based on UTCI for operative warning purposes in Italy. To increase accuracy of the basic biometeorological parameters, Global Forecast System (GFS) at 0.5° are used as initial condition to feed Limited Area Model (LAM) configured to work at high spatial resolution (12 km) by using all schemes and parameterizations suited to perform a more realistic simulation of the earth boundary layer, taking into account the soil and surface interactions. Hourly maps of thermal comfort/discomfort according to UTCI are provided with a forecast up to 5 days. Potentially, this operational chain could easily be implemented in more performed models (i.e. the 3-km ECMWF) and could also be used in specific UTCI health warning systems for vulnerable people. An evaluation of the potential UTCI application in Heat-Health warning system addressed to workers (HEAT-SHIELD Project-grant agreement No. 668786) was realized and in particular a microclimatic monitoring in three outdoor environments (Italy) was carried out during summer 2017.
2nd International Forum on Climate Change and Health Response under the "Belt & Road"
Initiative. Guangzhou, China. Asia International Hotel, No. 326, Huanshi East Rd, Yuexiu District, Guangzhou City.
The HEAT-SHIELD Personalized Warning System for European Workers and Other Adaptation Solutions to Minimize Detrimental Health and Productivity Effects of Workers Caused by Global Warming
Morabito M, Messeri A, Crisci A, Orlandini S., 2018
Globally, various heat-health warning systems (HHWSs) based on different environmental and health indicators exist that provide short-term (3-5 days) heat stress alert levels referred to the general population or the most vulnerable people, such as the elderly. These systems provide a generalized warning addressed to a standard person, with fixed anthropometric and behavioral characteristics (clothing worn and physical intensity). Therefore, the information provided may vary widely depending on personal characteristics. Currently, there are not personalized HHWSs for workers who, for strictly economic reasons (linked to the work productivity), are particularly vulnerable to the heat effects, as it is not possible generally to interrupt work except for limited periods. For this reason, in the framework of the European HEAT-SHIELD project (grant agreement No. 668786), a prototype of web-platform with personalized forecast heat warnings for workers, employers, organizations and operators responsible for safeguarding the health in various occupational areas, was also developed and launched operationally during the summer of 2018. This tool provides detailed short-term warnings (up to 5 days) and a medium-term planning support (up to just over a month). The system is based on probabilistic medium-range forecasts of ECMWF (European Center for Medium-Range Weather Forecast) calibrated on approximately 1,800 weather station located in Europe. The HHWS is based on the forecast of the worst daily heat stress condition assessed by the Wet-Bulb Globe Temperature (WBGT) index. A user (worker or stakeholder), after logging on the webpage http://heatshield.zonalab.it/, has access to the own personalized profile where the 5-day heat-risk
levels, with behavioral suggestions to be adopted in the short term (how much to hydrate and rest), as well as the heat-risk levels for planning work activities in the medium term, are available. This adaptation tool, together with other adaptation solutions that will be presented, represent useful b,c support for the worker to counteract the heat stress in the context of the global warming. This is also helpful for the employer (or who is responsible for safeguarding the health of workers) for a better planning of activities (i.e. shifting working hours) while preserving worker’s health and limiting the productivity loss.
UNIFI - IBIMET, Italy
9 October 2018, Split, Croatia
Labor productivity losses due to heat stress in agricultural workers:quantification of possible benefits deriving by worktime shifting
Introduction: When heat-stress condition occur, the intervention of worker breaks reduces worktime and labor productivity with consequent economic impacts. However, also easy preventive actions, such as worktime shifting, could reduce these effects. Methods: Meteorological data were collected during the summer period (June- September) of 2017 by a station located in a Tuscany agricultural farm (province of Florence) participating in the case studies organized within the European project HEATSHIELD (EU grant agreement No.668786). The hourly % productivity loss due to heat stress was estimated for moderate work activities (300 W) by using two risk functions:
a) based on ISO-standard (ISO, 1989); b) based on epidemiological data (Kjellstrom, 2017). Possible benefits deriving by shifting the working time were also assessed. Results: The daily average WBGT value during the typical working hours (from 8:00 to 17.00) recorded at the farm was 24.6°C with daily maximum WBGT values above 31°C in July and August. The daily mean % productivity loss during the typical working hours was higher when the ISO-standard was applied (6.1%) than the epidemiological approach (4.2%). The daily mean % productivity loss significantly (p<0.01) decreased by shifting the working time by two hours (from 6.00 to 15.00): the mean % productivity loss was 3.5% and 2.5% by using the ISO-standard and the epidemiological risk function respectively.
Conclusions: The heat-related productivity loss for moderate work activity can be more limited if a risk function based on epidemiological data is applied rather than the ISO-standard. The typical productivity loss expected in agricultural workers during the hottest season might be significantly reduced by worktime shifting. Because the exposure of workers to heat-stress conditions is expected to increase as a result of climate change, also simple adaptation measures might be of great help for preventing heat-related illness of workers and for reducing the productivity loss.
UNIFI - IBIMET, Italy
9 October 2018, Split, Croatia
HEAT-SHIELD tools for short-term warnings and long-term planning:heat-stress protection strategies to reduce the impact on different working environments and activities.
Introduction: Workers are at risk of excessive heat exposure and related negative effects. The HEAT-SHIELD project (EU grant agreement No.668786) aims to develop solutions to protect the health and productivity in workplaces from excessive heat in the context of climate change. Methods: The daily probability of exceeding WBGT heat stress thresholds was estimated with the ECMWF model to produce personalized short-term heat warnings for workers in outdoor sun/shadow activities. ISIMIP modeling scenarios produced monthly long-term heat planning information (www.ClimateCHIP.org). Field tests produced information on heat exposures and occupational health and productivity impacts. Results: The short-term warnings allow workers to obtain personalized information about the heat-stress impact with preventive suggestions to adopt in workplaces. The longer-term estimates allow enterprise planners and the community to consider likely future heat-stress problems. This is important for planning concerning new factory locations and design, as well as work scheduling in longer-term processes. Detailed local micro-meteorological data was collected in the summer of 2017 and 2018 in some Florence (Italy) workplaces. The workers declared a heat stress level (from low to more often moderate heat stress) even if the ISO-standard WBGT threshold for that activity level does not recommend critical heat-stress conditions. Conclusions: The features and the potentialities of these HEAT-SHIELD tools for worker’s health and productivity protection will be useful to implement adaptation solutions and mitigation strategies to reduce the severity of heat exposure and the impact on productivity. A ISO-standard WBGT threshold re-calibration is suggested and the consideration of the impact of the outdoor heat stress condition on indoor non-airconditioned environments is desirable.The short-term heat protection warning and long-term heat protection planning inform occupational health management and enterprise planning and will reduce heat-stress impacts on different working environments and activities.
International Forum on Climate Change and Health under the Belt and Road Initiative
Department of Health Policy & Management, School of Public Health, Sun Yat-Sen University, Guangzhou 510080, China
HEAT-SHIELD tools for protection of health and productivity in workplaces: new approaches to short-term warnings and long-term planning.
Morabito M, Messeri A, Kjellstrom T, Flouris A.D., 2017.
Around a third of the world’s population actually faces deadly heatwaves and this percentage will grow to about 50% by 2100 even if greenhouse gas emissions will be drastically reduced. Working people are at particular risk as their physical activity generates internal heat in the body. The European HEAT-SHIELD project (grant agreement No.668786) is focused on this topic, aiming to develop preventive solutions to protect the health and productivity in workplaces from excessive heat. The consequences of different levels of climate change will create motivation for climate change mitigation. In addition, new adaptation tools are developed: 1) short-term heat warnings based on probabilistic weather forecasts; 2) long-term heat planning based on climatological modeling
scenarios. The first tool uses the European Centre for Medium Range Weather Forecasts to assess the daily probability of exceeding a determined Wet Bulb Globe Temperature (WBGT) level for different types of work activity. Tests during the summer of 2017 in Florence, Italy, indicated, for instance, the need for heat protection actions in subsequent stressful summer working days. The second tool creates monthly long-term heat planning information with mean and maximum WBGT recorded over recent decades or predicted by using global climate models based on future greenhouse gas emissions depending on mitigating actions. For example, these planning data show in the city of Seville, Spain, that in the middle of this century there will be 4 months of afternoon WBGT levels in the shade above 26°C (on average), a level that affects workers health and performance. Twice as long period as during recent years. The features and the potentialities of these HEAT-SHIELD tools for worker’s health and productivity protection will be shown and discussed, highlighting the advantages of shortterm heat protection warning and long-term heat protection planning as a part of occupational health management and enterprise planning.
18 October 2017, Madrid, Spain
10º Taller PTEC (Spanish Construction Technology Platform) “La innovación en procesos de construcción de cara a la mejora de la seguridad y la reducción de la siniestralidad”
The effect of heat on the health and productivity of construction workers.
(Yanez P., Socorro R.)
It is estimated that about half of the economic cost of climate change over the next 15 years will be due to higher temperatures in the workplace, both as a result of lower productivity and health care costs. ACCIONA Construcción's R&D centre has carried out a field study on a residential construction project. During the project, 15 employees between the ages of 20 and 55 and different functions on site were monitored. The analysis of these will allow us to design measures to minimize the effects of heat on their workplaces.
September 3 - 7, 2017. Durham, UK
International Congress of Biometeorology
Validation of the human thermoregulation model to predict physiological impact of a heat wave (Psikuta A., Koelblen B., Annaheim S.)
High temperatures in summer with a higher probability of incidence of heat waves in response to climate change may dramatically reduce the thermal comfort of the inhabitants of urban areas. It has been demonstrated that higher daytime temperatures and reduced night-time cooling associated to heat waves can affect human health by contributing to general discomfort, respiratory and cardiovascular difficulties and exhaustion, and higher mortality, especially in sensitive populations, such as children, elderly and those with existing health conditions. This issue can be addressed with simulation tools such as validated models of human thermoregulation to develop effective preventive strategies and to mitigate heat exposure of individuals including its effects on their well-being and health. The major challenge posed on such models is the simulation of the exposure to outdoor conditions with continuous variability of the ambient parameters, which may affect stability and accuracy of the model. The second challenge is the necessity to simulate long-term exposures to capture effect of the heat wave lasting typically for several days, where any inaccuracy of the model algorithms will cumulate over time.
In this study we have validated human thermo-physiology model by Fiala using human experimental datasets collected during outdoor exposures with ambient conditions changing on a minute basis. Secondly, we have attempted to simulate the long-term exposures to validate parameters critical for human health and well-being using exposures based on the literature survey. The analysis revealed the opportunities of the human thermoregulation modelling in prevention of heat-related risks and showed the model shortcomings that need to be addressed in the further modelling and research endeavours.
Geophysical Research Abstracts
Vol. 18, EGU2016-12146, 2016
EGU General Assembly 2016
© Author(s) 2016. CC Attribution 3.0 License.
Modelling of labour productivity loss due to climate change:
Tord Kjellstrom (1) and Hein Daanen (2,3,4)
(1) Health and Environment International Trust, Nelson, New Zealand (email@example.com),
(2) TNO, Soesterberg, Netherlands (firstname.lastname@example.org),
(3) VU University, Amsterdam, Netherlands,'
(4) Amsterdam University of Applied Sciences, Amsterdam, Netherlands
Climate change will bring higher heat levels (temperature and humidity combined) to large parts of the world. When these levels reach above thresholds well defined by human physiology, the ability to maintain physical activity levels decrease and labour productivity is reduced. This impact is of particular importance in work situations in areas with long high intensity hot seasons, but also affects cooler areas during heat waves. Our modelling of labour productivity loss includes climate model data of the Inter-Sectoral Impact Model Inter-comparison Project (ISI-MIP), calculations of heat stress indexes during different months, estimations of work capacity loss and its annual impacts in different parts of the world. Different climate models will be compared for the Representative Concentration Pathways (RCPs) and the outcomes of the 2015 Paris Climate Conference (COP21) agreements. The validation includes comparisons of modelling outputs with actual field studies using historical heat data. These modelling approaches are a first stage contribution to the European Commission funded HEAT-SHIELD project.
7-12 October 2018, Split, Croatia
7th International Conference on the Physiology and Pharmacology of Temperature Regulation (PPTR 2018)
(Casanueva A., Kotlarski S., Spirig Ch., Fischer A.M., Flouris A.D., Kjellstrom T., Lemke B.,Nybo L., Schwierz C. and Liniger M.A.)
Global mean temperature is projected to increase until the end of the 21st century under all emission scenarios. Likewise, temperature extremes such as the highest daily temperature, the number of tropical nights or heat wave intensity and duration are projected to increase. These changes will ultimately affect biodiversity and human beings. Under hot conditions the human body is able to regulate its core temperature via sweat evaporation, but this ability is reduced when air humidity is very high. These conditions of high temperature and humidity invoke heat stress which, in turn, may cause heat-related illnesses (e.g. dehydration, hyperthermia and heat stroke). Heat stress is a major problem for vulnerable groups of the population and also constitutes an important threat for European workers with potential major impacts on workers’ health and productivity. In this context, the H2020 project HEAT-SHIELD (http://www.heat-shield.eu/) aims at analyzing the impact of climate change related heat increase on labour productivity in strategic industries in Europe within an inter-sectoral framework, bridging the gap between meteorological information and sustainable solutions.
Within HEAT-SHIELD, climate change projections of occupational heat stress are developed as the climatological basis for further physiological, economical and sociological analyses. We use a well-defined heat stress index (the Wet Bulb Globe Temperature) that is implemented by the International Standards Organization as regulatory index to measure the heat stress of working people. The comprehensive and state-of-the-art regional climate model (RCM) ensemble of the EURO-CORDEX initiative is exploited and statistically adapted for more than thousand locations in Europe to derive climate change signals assuming different emission scenarios. These are further used to obtain the potential losses in labour productivity following the recommendations of international standards. Our results show that, in large parts of Europe, future heat stress will exceed critical levels for a physically-active human body. The losses in labour productivity are especially large for non-shaded conditions, resulting in a reduction of 15-60% working hours during summer time in the Mediterranean area under the strongest emission scenario for the end of the 21st century. Adapting European industries to these projected changes will likely be required in order to prevent major consequences for the health of workers and the economic productivity. Such adaptation is already valuable today and may support workers to cope with current heat stress situations. An early-warning system has been developed for the detection of heat stress episodes up to four weeks ahead by applying the same methods to operational ensemble forecasts of the European Centre for Medium-Range Weather Forecasts. The system aims to allow stakeholders timely and precise prevention strategies and better planning of the work activities.
University of Ljubljana,
3-5 July 2018, Banja Luka, Republika Srpska, Bosnia and Herzegovina
International Scientific Conference on Climate Change Adaptation in Eastern Europe
Aggravated occupational heat stress recognition and mitigation in Slovenia (Pogačar T., Žnidaršič Z., Črepinšek Z., Kajfež Bogataj L.)
Global warming is strongly reflected in an increase in the number of hot days and, consequently, heat waves – their occurrence over a wider time frame, their duration, intensity and frequency. Changed characteristics were studied at two locations in Slovenia, confirming the increase. The problem of heat stress, health risks and labor productivity loss experienced by workers is well studied in hot locations, but not enough in Europe. Heat stress relies on both environmental and individual factors and it is important to understand how the general public and workers perceive heat risk, since this information may be helpful in preparing or updating heat stress mitigation strategies. Two studies were conducted in Slovenia in the frame of the Horizon 2020 Heat-Shield project, the first analyzing already experienced heat stress symptoms and health issues, productivity loss and self-initiative measures among workers in various sectors (N=687), and the second investigating workers' knowledge of heat stress, its impact and preventive measures (N=117). Workplace temperature in a large majority of cases was considered not suitable, negative heat stress impacts were recognized and already experienced. The results of the two studies show the importance of the problem, which is expected to worsen due to climate change, making mitigation of heat stress an unavoidable issue.