Heat stress
The total heat load on a worker from body heat, the environment and clothing.
Definition, in the source's words
NIOSH, Criteria for a Recommended Standard: Occupational Exposure to Heat and Hot Environments (Pub. 2016-106), Glossary(opens cdc.gov in a new tab)“The net heat load to which a worker is exposed from the combined contributions of metabolic heat, environmental factors, and clothing worn which results in an increase in heat storage in the body.”
What it means
NIOSH separates heat stress (the load) from heat strain (the body's response to it). All three contributors count: a mild day can still mean heat stress for someone doing heavy work in impermeable coveralls.
Example
Two workers face the same WBGT. One does light inspection in cotton; the other shovels in a chemical suit. The second has far higher heat stress because of metabolic heat and clothing.
Where it appears on the exam
ASP: ASP11 Domain 6, Industrial Hygiene and Occupational Health
Practice: Heat Stress (NIOSH Criteria), Heat Index, WBGT and Wind Chill Calculations
CSP: CSP11 Domain 6, Occupational Health and Applied Science
CHST: CHST5 Domain 2, Emergency Preparedness, Incident Investigation, and Response
Practice: Heat Illness Prevention and First Response, Heat Index, WBGT and Wind Chill
Questions
- What's the difference between heat stress and heat strain?
- Heat stress is the heat load on the worker. Heat strain is the body's physiological response to that load.
Related
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