Has anyone else gone through this?

My daughter of 1 year 2 MO whenever she gets a fever and the fever is done with after she starts getting this “rash” all over her body and it’s only when she gets a fever this is her third time getting it. My mom said all babies react different when they get sick. She said one of her coworkers son who is know 5 has the same issue when ever he would get a fever he would also get a rash all over the body it’s been having since he was small. I mean is this normal? Has this happened to any of your kids? Reacting to a fever afterwards idk what to think the rash always goes away within few days but I can’t imagine my baby going through this for ever 😥