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You have probably noticed that you feel hotter on a humid day than a dry one. Our bodies use perspiration to protect us from too much heat. In humid or moist air, sweat cannot evaporate as easily so we retain more heat.
Since both humidity and temperature can make us uncomfortable, Environment Canada developed a scale called the humidex to describe the effects of a hot and humid day. The humidex combines the effect of both temperature and humidity. Together, these are a better measure of the degree of discomfort than either one alone. The resulting number explains how the temperature feels.
As temperature and humidity increase, so do your chances of suffering a heat-related injury such as heat exhaustion or stroke. Use the humidex to determine how hot it actually feels on a given day. Protect yourself and your family accordingly.
We all run the risk of suffering heat-related injuries if we overexert ourselves outdoors on a hot day. However, some are at higher risk. Infants, small children, the elderly and overweight are most at risk. Health conditions such as heart disease and poor circulation can affect our ability to cool down. Alcohol or drug use also play a role. If you are at risk, or caring for someone who is, take extra care.
On hot days, be aware of the humidex in weather forecasts from Environment Canada or your local weather sources. Use the measurement as a guide in deciding what to do on a given day.
When the humidex is less than 29, people generally are quite comfortable outside and run little risk of suffering from the heat. When the humidex approaches 35 or higher, consider cutting back on outdoor activities that involve physical exertion. This is especially important if you belong to a group at risk in the heat. When the humidex is above 40, it is recommended that unnecessary outdoor activities be reduced or stopped.
That being said, outdoor physical activity is important to health. If you choose to go outside on a hot day, remember to protect yourself by following these tips.
If you do not have an air conditioner, go to a library or local mall for a few hours. Taking frequent cool showers or baths is another effective way of cooling off.