hi. I have read your question and understand your concern. sharp pain as if someone is pricking with needles specially during hot weather is quite characteristic is miliria rubra. it s commonly known as prickly heat. it s a very common problem in hot and humid climate. i suggest you apply calamine lotion twice daily and take a antihistamine like tab cetrizine once a day. along with these please follow the below instructions: 1. try to avoid hot humid weather 2. wear only loose cotton clothes 3. take bath twice daily with cold water a common practice is to use talcum powder over prickly heat. please avoid that as talcum blocks the sweat pores and increases the problem. hope this helps. for any further questions please get back to us. thanks.