Well, we should never forget that beating the heat is not possible. We can just reduce its effects on us.
And to be cool in summer or to reduce the effect of heat you can do following 8 things: -
1) Drink as much water as you can. It is very important to stay hydrated specially in such hot weather. Drink more in the day, and quarter of it at night.
2) keep exessive sweat far as possible. Sweating is a bug issue in summer so try to overcome that. Wear thin or cotton clothes. Cotton clothes can absorb your sweat.
3) keep your food cool, you may like to go out and eat outside but those junk are not good for health.
4) exercise comfortably even while its hot. The weather may be hot but it doesnt mean you have to skip exercise or dont do it. Do it properly.
5) keep all windows open whole day. You can close them at night.
6) while you are sleeping stay cool. Switch on the ac or fan and sleep well. Dont let your body temperature to rise.
7) understand your bodys best cooling points
When its too hot to handle, you can cool down yourself by placing a piece of ice cube wrapped up in a cloth above your pulse points like neck, wrists, etc which cools down your body quickly.
8) last tip , keep a mosquito killer ready because when the rainy season starts, mosquito will be your primary problem.