old think: If your child suffers from vomiting, lethargy, muscle cramps, or other early signs of a heat illness, give him lots of cool water to drink.
new think: He should drink an electrolyte solution instead.
why: Giving your child only water can lower the body's sodium level even more, which can lead to seizures. Instead, if he´s between 6 months and 2 years old, give plenty of an electrolyte solution such as Pedialyte. For kids older than 2, offer a drink like Gatorade. It's not possible for him to drink too much; the more he urinates, the better off he´ll be. In the meantime, loosen any tight clothing and have him rest in a cool environment. If he does not bounce back within an hour, if his temperature seems elevated and he's not sweating, or if he exhibits changes in his mental status, seek prompt medical attention.