Suggest Remedy For Itchy Rashes With Low Grade Fever

My 5 year old has been running a low grade fever for 3 days, and off and on a rash all over her body. Now we see weird bumps on her tongue. She's not eating, but drinking well. She started vomiting the first day, but not since. Also, the day she got sick, she was in the sun a lot. I can't tell if the rash is from a sunburn or sickness, but she itches a lot.