Thanks for query on HCM. Hives is also called urticaria. It is usually indicates some allergic reaction. You have to be watchful for triggering factor. It might be due to exposure to certain chemical,irritant,perfumes,after some food,using any body lotion,soap,after insect bite and even after excessive exposure to sunlight. It s often impossible to find out exactly why hives have formed. Apply cool compresses or wet cloths to the affected areas. Apply calamine,aloevera lotion for cool effect Try to work and sleep in a cool room,Wear loose-fitting lightweight clothes. Take anti histaminic during episodes.