I get really itchy when i get hot or do anything physical. i get red marks. i have taken tablets but it hasn't worked, its unbearable. can you help?

MiliariaCrystallina?: Some people have been known to get leg itching and rashes from running (cause is unknown). If it is from histamine release, one can try taking Claritin (loratadine) or Zyrtec, 1/2 hour before running. If it is from the cold, try wearing sweats. If it is from blocked sweat glands, try a sauna 3 times a week. Maybe one can make a dermatologist appointment, and then run to the clinic to show a fresh itchy rash.