<s>[INST] My Son is 2 and a half and layely he has had a red rash over his entire body that is only slightly raised. He is not showing any syptoms, no fever, coughing, stuffy nose, breathing problems, ect. Only when is he gets hot or heats up ( such as when he got out of a hot bath or was running around our home) the rash seems to get more raised and getes even redder. [/INST] Hi... Thank you for consulting in Chat Doctor. By what you quote it should be an urticaria or a simple skin allergy. You can use HY Chat Doctor.  Most important thing to be remembered is that it has a propensity to recur (called as second crop) within 10-14 days. If this happens, you can start using the same medicine, but I suggest you get the kid evaluated with your pediatrician. Hope my answer was helpful for you. I am happy to help any time. Further clarifications and consultations on Chat Doctor are welcome. If you do not have any clarifications, you can close the discussion and rate the answer. Wish your kid good health. </s>