How Exercise Works

Heat Stroke

Evaporation of sweat is an important cooling system that can efficiently remove heat. However, if exercise is done in a hot, humid environment, then sweat does not evaporate. This reduces the efficiency of this system and the person is subject to heat stroke. Heat stroke is a life-threatening condition. Here are its symptoms:

  • The core body temperature rises above 104 degrees F (40 degrees C)
  • Sweating stops
  • Heart rate increases
  • Respiration increases
  • Confusion, dizziness, nausea and headache occur

Heat stroke can cause a person to collapse, lose consciousness and even die. Emergency medical help involves these two steps: lowering the body temperature (removing clothing, spraying the person with cool mist, putting on ice packs, immersing the person in ice water) and replacing fluids, if possible.


You can avoid getting heat stroke by wearing shorts and other loose clothing, drinking plenty of water or sports drink and exercising in cool weather (below 82 degrees F or 28 degrees C).