Filed under: Sweating
Sweating is a normal, healthy response to exercise or to a hot environment—it’s our body’s way of regulating temperature. When sweat evaporates, it takes your body heat with it, which cools you down. But did you know that how soon you start sweating also indicates how fit you are? Fitter folks start sweating sooner, and sweat more, than the folks who are not as fit. It seems a conditioned body recognizes the change in environment (or circumstances) sooner responds more quickly than an unconditioned (less fit) one. While sweat isn’t generally a good indicator of how hard you’re working out, or the intensity of exercise, it may be a sign of how conditioned you are.
Note that, while men generally sweat more than women do, it doesn’t mean that men are more fit than women. Men and women even have the same number of sweat glands, but men’s sweat glands produce more sweat per gland.
So next time you find yourself changing out of a sweat-drenched shirt, be proud! You trained hard for that sweat!
Sweat is a critical function when you’re performing in hot environments. As your body absorbs heat from the environment, your nervous system activates sweat glands to release sweat. The moisture on your skin then evaporates, taking heat away from your body and cooling you off.
Protective clothing impedes the evaporation of sweat and the heat exchange between you and the environment, a condition known as “evaporative resistance.” This means that the exposed parts of your body will cool off more quickly than the parts that are covered, but they are also more prone to insect bites. Reports from Marines and National Park employees feeling “excessive heat” and a loss of sweating sensations after applying moderate to high amounts of DEET to their skin brought the safety of this insect repellent into question.
In a recent study, researchers found that when 33% DEET lotion is applied according to military protocol, it does not interfere with sweat production or other physiological responses. Nor does it interfere with the evaporation process necessary for cooling to take place. Researchers concluded that 33% DEET can be worn safely during military and occupational activities performed in hot, insect-infested environments. Similar studies have found oil- or alcohol-based repellents may increase core temperature by reducing sweat evaporation rate but do not affect sweat production. The military-approved form of DEET is polymer-based.
You can watch a YouTube video about the science behind the study.
DEET is considered by the EPA to be a toxic pesticide. It should be used with caution and as directed. More information about DEET, its uses, and warnings can be found on the EPA fact sheet. As of 2004, DEET was considered safe for use on children older than two months of age. Specific information on its use and effect on children can be found in the EPA TEACH chemical summary.