Joint and muscle damage
Some people think they can stretch deeper in the heat. But overstretching your muscles actually backfires and can lead to joint problems, inflammation, and arthritis. Orthopedic surgeons are seeing more and more yoga injuries.
Avoid overstretching. You should feel tension, not pain. Hold the stretch; never bounce. That can cause small muscle tears.
Infection
Hot, humid gyms can be a breeding ground for germs.
Don’t share mats, towels, or clothing with others. If you use a gym mat, cover it with a clean towel, or clean with alcohol spray or wipes. Bandage any cuts or scrapes. And if the room is dirty or wet with sweat, leave.
So remember, anytime exercise is conducted in extreme temperatures, it’s important to remain hydrated and to watch signs for overheating