New Delhi: The summer is round the corner and it's time to check your car's coolant level to guard against overheating. But what about your body? Doesn't it need something special to adjust to the expected gradual increase in mercury over the next few weeks?

It does, say nutritionists and health experts, who recommend nothing but water - in liberal quantities - to keep you properly hydrated.

Water makes up about 60 percent of your body weight. Every system in your body depends on water. For example, water flushes toxins out of vital organs, carries nutrients to your cells and provides a moist environment for ear, nose and throat tissues.

Lack of water can lead to dehydration, a condition that occurs when you don't have enough water in your body to carry out normal functions. Even mild dehydration can drain your energy and make you tired.

Palliative care physician Divya Pal Singh said: "Proper care needs to be taken of the body's fluid requirement as the weather starts getting warmer."

"Drinking adequate amounts of water also ensures that cancer causing toxins are flushed out of the body," he said.

"Your water needs depend on many factors, including your health, how active you are and where you live. At least two-three litres of fluids daily should keep a person healthy," he said.

The doctor warned fizzy drinks or juices aren't the ideal replacement for water.

Naturopath Gita Mehta said: "If you don't find plain water exciting enough, try a lemonade or packaged flavoured water. This is much better than sugar-rich colas and juices that the body fails to break down fast."

"Water in any form, even the flavoured variant, delivers instant rejuvenation. It enters the blood in no time, maintaining the ideal body temperature. But the process is not as effective and fast with colas and juices," Mehta said.

Ajay Kansal, a consultant in pathology and author of "The Evolution of Gods", said: "During the last few decades, most upwardly mobile Indians, especially youth, have adopted a peculiar habit of having meals with some drink such as sweetened juices, colas or other fizzy drinks."

"These drinks invariably contain high amount of calories and preservatives. In place of these fancy drinks, I would suggest water or a drink with minimal sugar and no preservatives or something with an added dose of vitamins," he said.

Parents of small children have their own set of problems. Anjali Madan, a Delhi-based human resource consultant, complained about her eight-year-old son refusing to drink water in adequate quantities.

"He takes just a few sips of water after meals and a session in the playground. Since I do not want to give him colas, I am confused how to ensure his regular and proper hydration," she said.

While instant sweetened, flavoured additives and lemon concentrates are some of her tested ways of drawing her son into drinking more and more water, she said it was not practical to prepare such drinks all the time.

The HR professional said she was not really sure about the new breed of flavoured water, some of which even claim to carry benefits of vitamins, to improve her child's water drinking habit.

Said Steve Verma, director, Beltek Canadian Water Limited, which makes vitamin enriched water drink, Wild Water: "Our product is a natural alternative to colas and an exciting alternative to normal packaged water."

"We have focussed on tasty hydration and meeting the needs of calorie-conscious consumers," he said.

"Even children and reluctant water drinkers may get attracted to our natural flavoured water with vitamins," he said, adding that some of the variants of Wild Water came with the benefits of Vitamins A, B and C along with electrolytes and zinc.

"People moved away from carbonated soft drinks to juices and now are further shifting towards healthier, less calorific and more natural alternatives. Therefore, we see a positive future trend towards such categories," he said.

Verma claimed his product has opened a completely new category in the 300-crore functional drink market (excluding energy drinks). A functional drink is one that contains additives like herbs, vitamins and minerals, among others.

According to American NGO Institute of Medicine, an adequate intake for men is roughly three litres (about 13 cups) of beverages a day. For women, it is 2.2 litre (about nine cups) of beverages a day.

Nutritionist Ruchi Sharma maintains that water, in whatever form, is the best way to take on the harsh summer.

"For fussy kids the parents need to add lemon, squashes or flavours to water to get them into the habit of relying on water more than carbonated drinks," she said.

The bottomline is that water has to be consumed, in whichever form it is, to fight the summer heat, Sharma added.