I seem to get a red blotchy rash on my chest everyday and it get really warm and can't seem to find the cause of it ?

See a doctor: The best diagnostic technique for diagnosing a rash is seeing and sometimes feeling it. With years of experience, doctors see many rashes from many different causes and good at diagnosing most rashes on sight. Proper diagnosis is key for making treatment recommendations. The accompanying picture is of a classic appearing rash known as tinea corporsis. Scratching may cause the rash to spread.