Heat Stress

Sun Smart Saskatchewan’s focus is skin cancer prevention, but there is another health concern associated with time spent outdoors; heat stress.

Heat stress


Signs & Symptoms

Climate change

The sun and your health

Heat Stress

Heat stress happens when your body loses its ability to self-regulate body temperature. There are a several health issues caused by heat stress, including heat rash, heat cramps, fainting, heat exhaustion and heat stroke. The most serious is heat stroke, which can cause irreversible damage to the heart, lungs, kidneys and liver.

Are you at risk?

What contributes to heat stress?


High air temperature and humidity contribute to heat stress.

The humidex is a measure of how hot we feel based on both high temperature and humidity (the level of moisture in the air). A higher humidity will generally make the environment feel hotter. The higher the humidex, the higher the risk of heat stress.


Everyone handles heat differently. There are personal factors that contribute to your risk for heat stress.

Dehydration, improper clothing, pre-existing medical conditions, lack of acclimatization (how your body copes with a hot environment), use of some medications, and poor physical fitness can contribute to heat stress.

Physical Exertion

Working or exercising outdoors during hot and humid conditions can contribute to heat stress.

Outdoor workers are at an increased risk for heat stress.

Be heat aware

Signs and symptoms of heat stress

Call an ambulance if you suspect that someone has heat stroke. Heat stroke can result in death.


Heat rash

Red bumpy, itchy rash.


Heat cramps

Painful cramps in the arms, legs or stomach. The cramps can occur during physical exertion or later on. Heat cramps can be a warning of other more dangerous heat-related illnesses.


Heat exhaustion

Heavy sweating, cool moist skin, body temperature above 38°C, weak pulse, normal or low blood pressure, tired and weak, nausea and vomiting, extreme thirst, panting or breathing rapidly, blurred vision.

Seek medical attention immediately for suspected heat exhaustion.


Heat stroke

High body temperature (over 40°C) and any of the following: weakness, confusion, acting unusually, , upset, or acting strangely; hot, dry, red skin (classic heat stroke); profusely sweating (exertional heat stroke); fast pulse; or headache or dizziness. In later stages, a person may pass out and have convulsions.

(Source: Sun Safety at Work Canada )

A growing concern

Heat stress and climate change

Heat waves pose a significant challenge to public health, and they are becoming more frequent and more severe because of climate change.  Over the next 30 years, the number of extremely hot days in a year is expected to more than double in some parts of Canada (Health Canada).

We are not all equally at risk during an extreme heat event. Heat related illnesses are of particular concern for vulnerable groups, including the elderly, very young, outdoor workers, and those who cannot afford access to cooling.

Municipalities and health authorities across the country are in various stages of preparing for these more frequent heat events.