As it turns out, sweating does cool the body. Here’s why: When we sweat, we lose heat through evaporation and that heat must be replaced somewhere in our bodies — either by increasing core temperature or reabsorbing water from the tissues. Sweating can thus take place even when your core temperature is below normal (e.g., at night when you go to bed), provided there’s enough moisture in the air for evaporative cooling to occur. In other words, if you have a fever and feel hot all over but your skin doesn’t actually burn up…you may still sweat!
What about during exercise? Won’t my body produce more sweat under stress?
Yes and no. Generally speaking, exercising will increase overall body temperatures compared with resting conditions; however, this occurs only because of a combination of factors including a higher basal metabolic rate (plus increased heart rate), elevated blood flow to working muscles due to exercise-induced vasoconstriction [the narrowing of blood vessels], and an elevated need for oxygen from exertion [from increased respiration]. All these factors cause increases in total energy expenditure relative to rest or sleep states where energy expenditure is relatively constant since there are no changes in activity level or intensity across time periods. In addition, most people experience small fluctuations in core temperature during physical activities ranging from slight elevations around 70–75°F (~21–24°C) following prolonged sitting/standing