During intense physical activity, the body's temperature rises above normal. Drinking cool water lowers the body's temperature to its normal range and replenishes water lost through natural perspiration.

During intense activity thirst sensors are inhibited, so it is easy for athletes to become dehydrated. A loss of only 3% of your body's water content causes a 10 % drop in strength and an 8% loss of speed. It is therefore important to drink more than the recommended minimum during intense exercise.

Skin is the body's biggest organ, and if you're dehydrated your skin suffers. As beauty experts know, water is nature's best moisturiser. Drinking sufficient amounts will re-hydrate your skin from the inside. Skin tends to become drier with age, so it is even more important to drink more water as you grow older.

Dehydration can affect you in more ways than you might think:

Detoxing is valuable for the body as it cleanses and rids the body of toxins which are present in the air we breathe, the foods we eat and in many drinks.

Toxic overload can lead to headaches, skin eruptions, constipation and that sluggish feeling in the morning. The body stores these excess toxins as cellulite or oily patches.

All detox programmes share one crucial element: water. Using water to detox, eating a healthy diet and exercising sensibly boosts the immune system and can give you lots more energy.

Over the age of six months, healthy babies and toddlers can be served any natural bottled waters that are low in minerals (without boiling).

The British Dental Association recommends that milk and water should constitute the majority of drinks for older babies (over six months) and toddlers. Natural bottled water has no calories, additives or sweeteners so is the ideal way to encourage children away from sweet soft drinks to achieve the correct level of hydration and stimulate efficient digestion. Nutritionists recommend children drink six glasses of water a day to maintain hydration levels.

Highland Spring For Kids provides a fun, cool, healthy alternative to sweetened soft drinks and is perfect for lunchboxes. It's 100% Scottish natural water, bottled at source from our organic catchment area. Calorie free, it's BDA approved as it's free from sugar, colouring or artificial additives and doesn't harm teeth.

Click here to view A spoonful of sugar? - Highland Spring's award winning report into the poor drinking habits of British children.

If you would like a Water is Cool in Schools Information Pack for schools or parents, please send a cheque for £5 for each, payable to ERIC to the following address:

ERIC (The Enuresis Resource and Information Centre),
34 Old School House,
Britannia Road,
Kingswood,
Bristol BS15 8DB.
www.wateriscoolinschool.org.uk

Experts advise that the average adult needs a daily intake of 1.8 litres of water in normal circumstances however this should be treated as the minimum if you are pregnant.

Dr Susan Shirreffs, an expert on dehydration from the University of Aberdeen comments: "The pregnant mother supplies all the baby's nutrients and removes all its waste products. Therefore, optimum hydration is desirable to supply nutrients and efficiently remove waste products". It is also important to note that dehydration can be a potential cause of 'morning sickness'; women who suffer should try to drink more water.

Fluid needs change dramatically through infancy and childhood but needs are greatest during the early months - it is crucial to avoid fluid losses in young babies, and indeed, this remains essential throughout childhood. Of course, it's just as important for mums to keep up their hydration levels; that headache blamed on lack of sleep could be the result of a lack of water!

Some experts believe that a lactating mother requires an extra 1 litre of fluid per day. However, other studies show that significantly increasing or decreasing fluid intake has no effect on milk production. Everyone's body is different and the best way to make sure you are properly hydrated is by checking the colour of your urine (the paler the urine, the better hydrated you are).

During all types of physical activity, heat is produced and fluid is lost from the body. The amount of fluid lost as sweat varies from person to person and is dependent on a number of factors including weight, fitness levels, exercise intensity, temperature and humidity, type of clothing worn, and the duration of the activity.

Performance may be impaired if an individual is dehydrated by as little as 2%. (In fact, during a marathon at high ambient temperatures, runners may lose as much as 8% of their body weight from fluid loss.) To avoid dehydration prior to a sporting event, The American College of Sports Medicine recommends drinking at least 500mls of fluid two hours beforehand, and during the event, Dr Marnie Sommerville of the Nutrition Training Company recommends drinking 500mls after the first 15 minutes and 150ml’s every 15 minutes thereafter. And don’t forget to rehydrate as soon as possible after the event to aid your recovery process.

Some practical tips for staying hydrated during exercise:

The body loses 1.5 litres of water a day through natural processes such as breathing and sweating. This is increased during hotter periods so it is essential to drink more water when visiting sunnier climes to help avoid heat exhaustion. You could also try pouring water over your pulse points to cool your body temperature. If you are in a country where it is advisable to drink only bottled water, avoid ice in drinks or desserts since they’re usually made using tap water, and remember to clean teeth with bottled or purified water. Finally, try to avoid alcohol during a flight and while sunbathing as this can lead to dehydration.