Keep an eye on it and if you are worried get to your GP. DD2 had roseola a couple of weeks ago. She had no symptoms but temps around 39-40. They hung around for 3 days and then 24 hours later she came out with a rash. Apparently it is one of the 5 viruses that have a rash in small children and nothing to worry about. Not saying this is what he has but he is about the right age.

I hope that they are gone now and he is back to his usual self!