Resources and Definitions

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image of workers and PPE

Resources and Definitions

NIH’s National Institute of Environmental Health Sciences Worker Training Program (WTP) has been working with its awardees and federal partners to better understand the risks that workers and communities face due to extreme heat and climate change. Click here to see their extensive list of resources that address occupational health and safety issues related to extreme heat, climate change, and ways to build individual and community resilience to the impacts of climate change.

 

Definitions: 

Acclimatization: Acclimatization is the process of your body adapting to repeated exposure to a hot environment. Improved sweating and cooling and the ability to work in hot environments at a lower core temperature and heart rate are examples of acclimatization. 

Heat Cramps: usually affect workers who sweat a lot during strenuous activity. This sweating depletes the body’s salt and moisture levels. Low salt levels in muscles cause painful cramps. Heat cramps may also be a symptom of heat exhaustion.

Heat Exhaustion: Heat exhaustion is the body’s response to an excessive loss of water and salt, usually through excessive sweating. Heat exhaustion is most likely to affect vulnerable populations like the elderly and people with high blood pressure who work in hot environments.

Common symptoms include heavy sweating, high body temperature, headache, nausea, dizziness, feeling weak, easily irritated, heavy sweating, elevated body temperature, decreased need to urinate. 

Heat Stroke: Heat stroke is the most serious heat-related illness. It occurs when the body can no longer control its temperature: the body’s temperature rises rapidly, the sweating mechanism fails, and the body is unable to cool down. When heat stroke occurs, the body temperature can rise to 106°F or higher within 10 to 15 minutes. Heat stroke can cause permanent disability or death if the person does not receive emergency treatment.

Heat Syncope: Heat syncope is a fainting (syncope) episode or dizziness that usually occurs when standing for too long or suddenly standing up after sitting or lying. Factors that may contribute to heat syncope include dehydration and lack of acclimatization.

PPE Heat Burden: The increased risk for heat-related illnesses caused by wearing PPE (e.g. waterproof aprons, respirators, surgical caps, additional layers of clothing, gloves, etc.).

Rhabdomyolysis (rhabdo) is a medical condition associated with heat stress and prolonged physical exertion. Rhabdo causes the rapid breakdown, rupture, and death of muscle. When muscle tissue dies, electrolytes and large proteins are released into the bloodstream. This can cause irregular heart rhythms, seizures, and damage to the kidneys.

Wet Bulb Globe Temperature (WBGT): A measure of potential heat stress while also accounting for environmental factors such as air temperature, sunlight exposure, humidity, radiant heat, wind speed, sun angle, and cloud cover.