Whenever i'm breaking sweat i am getting stinging feeling, pins and needles, hives-like redness and bumps all over the body. what should i do?

Maybe cholinergic ur: This might be cholinergic urticaria. It is a type of hive. Your physician can have you see a dermatogist. It is often brought out by exposure to heat

Heat rash: Suspect heat rash, which is actually irritation of the sweat glands. Cool, breathable clothing. seek shade. Cool bath after heat exposure. Use damp cool cloth to sooth rash when in the sun. Minimize exertion in warm environment. If these measures fail, mid-potency topical steroid is a consideration. Heat-induced hives is somewhat different and should respond to antihistamine such as cetirizine.

Allergies: These generalized hives may be caused by histamine released by your body temperature rising and an antihistamine like benadry or atarax(causes drowsiness) or Claritin (loratadine) May block the reaction. The allergy could also be due to something internal as well as external. An allergist is best qualified to evaluate and treat you.