My 15mo has had a fever of over 38 all day, goes down slightly with calpol but then straight back up again. His breathing is quicker than usual. Hes quite sleepy, but not confused. He has a bright red rash on the base of his thumb and what looks like heat rash all over his back. I have an appointment at a peads urgent treatment centre in 30mins. Im terrified. Please reassure me.