How does the body adapt?
Thermoregulation is the attempt to balance body temperature when heat gain and heat loss occurs as temperatures in changed surroundings can be very different. This is very important as high temperatures cause a lot of stress on the body leading to injury or in some cases even death. To deal with the differentiation of temperatures and climates, humans adapt to the environment. The skin naturally helps keep the body at a constant when the temperature of the atmosphere rises. The main response to help lose the excess body heat is by vasodilatation (red blood cells rising to the surface of the skin, this is when your face turns red) and sweating. The sweat evaporates from the surface of the skin aiding a cooling agent; however a lot of water is lost through this method. The hairs lie flat on the surface of the skin to prevent heat being trapped. It is very difficult for evaporation to occur when the environment is humid and reduces the effectiveness of sweating to cool the body.
What should you do?
When exercising in the heat plenty of fluids must be consumed to avoid injury from the heat, as humid conditions can lead to heat stroke and heat exhaustion. Appropriate clothing should be worn such as loose, light coloured and light-weight clothes. Also it is better to exercise early in the day or in the evening as these times is more arid. It takes around 7 to 14 days to acclimatize to different conditions therefore exercise should be increased gradually.
What are the risks?
Internal body temperature can exceed 40ºC during exercise and 42ºC in active muscles. However if the body does exceed 40ºC it can affect the nervous system and is unable to get rid of excess heat. The heat stresses the body as the muscles and skin compete for blood and heart rate decreases. As a result of dehydration, heat cramps, heat exhaustion and heat stroke can occur. Heat cramps are when the body is dehydrated and the blood system cannot deliver electrolytes (salts; potassium and sodium) for the working muscles to function. Heat exhaustion is where the body becomes disabled and does not have the ability to rid of excess heat, there is also a dramatic increase in Heart Rate. Heat stroke is the most fatal injury caused by the heat, the body starts to shut down all of its processes, this can happen anywhere above 40ºC.