My 8 year old son has a rash all over his body, his face is red and he has a temperature of 100.2? what could it be

Viral disease: There are hundreds of viruses that can cause diseases in people. People usually catch the virus from another person, and then have that particular virus only one time. Some virus infections are well known, like measles, mumps and chicken pox, but many don't have a popular name. Your son likely has a virus, with rash and fever, and it will go away by itself. Tylenol (acetaminophen) or Motrin for children will help.

Son's Rash: Morbilliform drug eruptions are very common, comprising 95% of all drug-induced skin reactions. Antibiotics are the most common cause. However the list is very long and includes herbal and natural therapies. In general, a morbilliform skin rash in an adult is usually due to a drug, but in a child is more likely to be viral. Thus, your child's rash is most liked caused by a viral infection.