Health, Hydration

Hydration Status and its Impact on Thermoregulation

It sounds fancy but thermoregulation is just the scientific term for the body’s ability to keep its temperature within a normal range. Our body temperature should be between 36.1oC and 37.2oC, with the average temperature being 37oC. The human body has many mechanisms which help to keep its temperature within the safe and normal range.


To understand how hydration can affect the body’s thermoregulation properties, it’s good to know how thermoregulation itself works. The body’s temperature is ultimately controlled by a section of the brain which links the nervous system with the hormonal or endocrine system, called the hypothalamus. If the body’s temperature varies in either way hormones help to initiate the control mechanisms which will get the temperature back to normal.

Hot conditions

If you are exposed to hot conditions such as hot weather then the body will start to do things to help keep itself cool, such as:

  • Sweat glands under the skin produce sweat which is mainly made of water and some ions, hence the salty taste. The sweat travels up through ducts, through a sweat pore and onto the surface of the skin where it evaporates and helps the body to cool down.
  • Tiny muscles under the surface of the skin relax causing the hairs to lie flat. This motion prevents still air becoming trapped between the hair and encourages air flow which in turn increases heat loss.
  • The smooth muscle walls of arterioles, small branches of arteries which lead to capillaries, relax allowing a greater flow of blood through the arteries. This helps to redirect blood to the capillaries which are closest to the surface of the skin and increases heat loss.

If the body is exposed to environmentally hot temperatures above that of the core body temperature, sweating is the only way the body can cool itself down.

Cold conditions
  • Heat is lost through the extremities such as hands and feet.
  • The body decreases sweat production.
  • The muscles under the skin contract causing the hair follicles to sit upright and this causes hairs to stand on end. The hair acts as an insulating layer because humans have little hair on their bodies you may see this reaction to the cold in the form of goosebumps.
  • The body shivers if it is Shivering is caused by the hypothalamus sending messages to the muscles. Shivering uses energy and generates heat helping to warm the body back up.

Hydration and thermoregulation

When the body is exposed to high temperatures, one of its initial reactions is to sweat. Sweat contains water and persistent sweating can cause a significant loss of water from the body. Therefore, your hydration status is vital for your body’s ability to thermoregulate. In a temperate environment, the human body loses approximately 450ml of water every day. However, if this is coupled with exercising, the loss of water rises significantly.

You should keep yourself well hydrated throughout the day by taking small sips of water all day. Drinking like this will help to keep your water stores topped up. Remember though, if it’s hot outside or you’re exercising you will need to drink more to compensate for the increased loss of water.

Related Posts

Leave a Reply

Your email address will not be published. Required fields are marked *