Heat-Related Illness
Why is heat exposure at work important?
Hot weather and heat within the body during physical work can kill. Heat-related Illness (HRI) ranges from relatively mild conditions such as heat cramps to more serious illnesses such as heat exhaustion. The most serious form of HRI is heat stroke, which can cause death.
HRIs are preventable. Cases of HRI are expected to rise in the future with changes in the climate. Knowing the signs and symptoms of serious HRIs and how to prevent them can protect workers.
Resources for workers, employers, & others
Education, trainings, data summaries, and other resources are available for workers, employers, educators, policy makers, and others.
Heat-related illness tracking
Workers’ compensation data are used to track Washington State HRIs every year. Data are compiled to describe case counts and to identify high-risk industries and occupations.
Heat research
In addition to HRIs, heat exposure at work can cause heat-related traumatic injuries for example from falls from ladders. Heat exposure can also cause kidney injury, lower work productivity, and other effects. To better understand this burden, SHARP conducts research on patterns and disparities in health effects of workplace heat exposure.
Workers’ compensation HRI tracking
Annual Washington Accepted State Fund Heat-Related Illness Workers’ Compensation Claims (in English and Spanish)
Other data sources
Workers’ compensation data are not comprehensive. SHARP also works to develop methods to identify occupational HRIs using other data sources.
Employment Data in Washington’s Rapid Health Information Network (RHINO)
Research Topics
Occupational Heat-Related Illness
Occupational Heat-Related Traumatic Injuries
Occupational Mental Health Outcomes
Occupational Heat-Related Illness
Wuellner S, Turner K, Spector JT (2024). Emergency department visits for heat-related illness among workers: Occupational health surveillance using Washington syndromic surveillance data. American Journal of Industrial Medicine. https://onlinelibrary.wiley.com/doi/10.1002/ajim.23650
Spector, JT, Sampson, L, Flunker, JC, Adams, D, Bonauto, DK (2023). Occupational heat-related illness in Washington State: a descriptive study of day of illness and prior day ambient temperatures among cases and clusters, 2006–2021. American Journal of Industrial Medicine. https://onlinelibrary.wiley.com/doi/10.1002/ajim.23506 | Research Findings
Martell Hesketh, BA; S. Wuellner, PhD, MPH; A. Robinson, BA; D. Adams, BS; C. Smith, PhD, MPH; D. Bonauto, MD, MPH (2020). Heat related illness among workers in Washington State: A descriptive study using workers' compensation claims, 2006-2017. American Journal of Industrial Medicine. https://onlinelibrary.wiley.com/doi/abs/10.1002/ajim.23092 | Research Findings
June T Spector, Krenz J, Rauser E, Bonauto DK (2014). Heat-related illness in Washington State agriculture and forestry sectors. American Journal of Industrial Medicine. https://doi.org/10.1002/ajim.22357
David K Bonauto, Anderson R, Rauser E, Burke B (2007). Occupational Heat Illness in Washington State, 1995 – 2005. American Journal of Industrial Medicine. https://doi.org/10.1002/ajim.20517
Occupational Heat-Related Traumatic Injuries
Miriam Calkins, Bonauto D, Hajat A, Lieblich M, Seixas N, Sheppard L, Spector J. (2019). A case-crossover study of heat exposure and injury risk among outdoor construction workers in Washington state. Scand J Work Env Health. https://www.sjweh.fi/article/3814
June T Spector, Bonauto DK, Sheppard L, Busch-Isaksen T, Calkins M, Adams D, Lieblich M, Fenske RA (2016). A Case-Crossover Study of Heat Exposure and Injury Risk in Outdoor Agricultural Workers. PLoS One. DOI:10.1371/journal.pone.0164498 | Research Findings
Occupational Mental Health Outcomes
Florez-Acevedo S, Blancas MT, Spector JT. (2025). Occupational Heat Exposure & Mental Health Outcomes: A Review and Framework Incorporating Social Determinants of Health to Guide Future Research. Curr Environ Health Rep. https://doi.org/10.1007/s40572-025-00479-6 | Research Findings
Shade
Flunker JC, Spector JT, Blancas M, Briggs NL, Flores M, Whitaker CR, Schoonover T, Cardoso T. (2024). Farmworker-Relevant Heat Exposure in Different Crop and Shade Conditions. J Agromedicine. https://doi.org/10.1080/1059924X.2024.2365647
Resources for workers, employers, and others
Be Heat Smart (wa.gov)
Heat Illness Toolkit (PNASH)
Heat Illness Prevention Campaign | Occupational Safety and Health Administration (osha.gov)
General information
Heat Stress and Workers (NIOSH | cdc.gov)
HEAT.gov - National Integrated Heat Health Information System
Data summaries (SHARP Stats)
Heat-related Illness by Temperature