Water makes up about two-thirds of our body weight. And it's important for this to be maintained because most of the chemical reactions that happen in our cells need water. We also need water for our blood to be able to carry nutrients around the body.
As your body works it produces waste products and some of these waste products are toxic. The body gets rid of these toxins through the kidneys in urine, and urine is mainly made up of water.
We also lose water through evaporation when we breathe and sweat. As the temperature rises and as we do more activity, this increases the amount of water the body loses.
To stay healthy, you need to replace the fluids you lose. And don't forget, if the weather is hot or you are exercising, you will be losing even more water.
In climates such as the UK, we should drink approximately 1.2 litres (6 to 8 glasses) of fluid every day to stop us getting dehydrated. In hotter climates the body needs more than this. We also get some fluid from the food we eat.