Exercise Dangers in Hot and Humid Conditions

Exercising in hot and humid places can be extremely taxing on the body. The human body likes to keep tight control of its body temperature using several different systems. When you are training in extreme heat, an example might even be a construction worker in full gear on a sunny day, the main system the body uses to cool down is by sweating. Sweat forms on the surface of the skin and as it evaporates it uses heat energy from your body, thus taking heat away from your body, which intern cools you down. However, if you are in a humid location, evaporation becomes much more difficult.

Let's use the analogy of your skin being like a radiator of a car. When your core body temperature rises, it warms the blood and your heart pumps the blood to your skin to cool it down. When the sweat is heated, it evaporates in to the air just like when you boil a pot of water. Unfortunately, if the sweat does not evaporate and rolls off the body as a liquid, it does not have any cooling effect.

The body will maximize this cooling structure in two ways. The first way is to increase the heart rate which will pump blood faster to the skin. This will allow cooling of the blood much faster. The second cooling structure the body will utilize is to produce more sweat. The hotter the body becomes, the more sweat glands the body will use.

But how hot is too hot? There are many fancy and technical terms that are beyond the scope of this article. But as a general guideline, anything over 87f, or over 85f with relative humidity at or above 60%, is considered too hot to exercise and should be done with extreme caution.