Heat Stress Calculator

Calculate Heat Index, WBGT, and Thermal Work Limit (TWL) to assess heat stress and safety limits for daily life, sports, and industrial work.

Heat Index combines air temperature and relative humidity to give the "feels-like" temperature your body experiences. Used by weather services worldwide to issue heat alerts for the general public.
Apparent Temperature (Feels Like)
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Health Advisory

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WBGT (Wet Bulb Globe Temperature) is the international standard used by the Olympics, FIFA, military, and OSHA for heat stress in sport and outdoor work. It accounts for temperature, humidity, radiant heat from the sun, and air movement.
WBGT
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Activity Guidelines (ACGIH / Olympic)

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TWL (Thermal Work Limit) is an Australian / industrial standard (AS 2626) calculating the maximum safe metabolic work rate (W/m²) a person can sustain in a hot environment. Used in mining, construction, and foundries. Developed by Brake & Bates (2002).
Thermal Work Limit
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W/m² — max sustainable metabolic rate
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Work Level Limits (AS 2626)

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