Was using space heater close to the legs for 2months. i've stopped body parts ache for a week found skin rage between legs that hurts. what's wrong?

Need more informatio: There are a few possibilities but I need more information to answer your question. Do you have any health probs provide a picture of the rash On any medications or health products Is there a family history of diseases such as rheumatoid arthritis, lupus, skin diseases or autoimmune diseases. The rash may be a vasculitis or erythema nodosum but without some more history, cannot diagnose.

Erythema ab igne: Keep skin cool and well-ventilated. Will slowly resolve. If you need help, see a dermatologist.