My children had fever for 24 hrs and then down to low body temp..this has been happening for 5 days..temps go between 95.9-97.8 what could cause this?

Fever: Your child may be fighting off a virus or other mild infection. If the fever is over 101, your child is contagious until it stays below 101 for 24 hours. 98.6 is an average body temperature (which means that there is a range of normal temps). If he is acting fine, you can usually just observe and see if he has any other symptoms. A virus will usually run its course in 7-10 days.