Health conditions and their symptoms related to the heat include:
- Heat rash: clusters of blisters; rash
- Heat cramps: heavy sweating, muscle pains or spasms
- Heat exhaustion: heavy sweating; cold, pale clammy skin; dizziness, headache, nausea, fainting
- Heat stroke: fast, strong pulse; hot dry red skin; nausea, dizziness, fainting This is a medical emergency! Get medical help immediately!
Medical attention for fainting, heat exhaustion and heat stroke is crucial.
People can get used to working in the heat so they don’t react as badly to hot conditions. The acclimatization process usually takes a few weeks. When temperatures first rise during the warm weather season, people should break themselves in gradually by not working or exercising as hard until they are acclimatized.
How is the potential for heat stress assessed?
In addition to high temperatures, humidity, air movement (e.g. wind), radiant heat (e.g. direct sunlight or hot equipment), clothing, and how hard you are working or exercising also play a role in causing heat stress.
Health and safety professionals may use different kinds of indexes that combine measurement of these factors to assess the danger of heat stress. A commonly used index is called the Wet Bulb Globe Temperature (WBGT). It combines measurements for air temperature, radiant heat, and humidity. WBGT may be reported in terms of degrees Celsius or Fahrenheit.
Exposure guidelines for heat stress have been recommended by the American Conference of Governmental Industrial Hygienists (ACGIH). These guidelines are available on the Canadian Centre for Occupational Health and Safety (CCCOHS) website.
The Humidex is an easier way of assessing temperature conditions. It combines air temperature and humidity levels. Environment Canada reports the Humidex daily for your location on its website.
The following is advice from Environment Canada about Humidex levels: