DD2 (3.5) has had a temp of about 39 on and off for the past four days. When she has it she is lethargic, not her-self etc. but calpol seems to sort her out. Then she's fine for the rest of the day. She doesn't seem to have any other symptoms, cold, cough, and when I ask her she say that nothing is hurting just that she is tired. She is eating OK but less than normal. I;ve asked if she has tummy-ache or if her wee hurts - none of these.
Any ideas what this could be?