To tell you the truth it's absolutely normal to sweat in summer. It's absolutely necessary because if you don't you may have a heat stroke. Your sympathetic nervous system triggers off your sudoriferous glands, starting moisture evaporation off your skin thus lowering your body temperature.
So what our perspiration consists of ? 99% of it includes water, 1% - minerals like Na, K, Ca and so on.
How to beat this problem and avoid extra stress when we find ourselves in a very embarrassing situation by exposing our wet spots.
First try to wear more cotton and flax-made clothes. These fabrics absorb sweat letting the skin breath. Go to gym in close-fitting sport tights or shorts. They reduce rubbing of body parts and perspiration. Use modern anti-perspirants as they block 40% of sudoriferous glands. Take cold showers before leaving the house. It will contract your glands and cool down your body.

And of course try to control your emotional state. Take things easy and stay calm. If you