Today was the 3rd time this has happened. My son wakes up with a fever (102.4 F) and complains that his foot hurts (his right foot), He has me put ice on it. I give him Advil for the fever and within an hour he says his foot no longer hurts but he starts vomiting. The last time this happened it last 3 days and it was only when he would wake up the his foot would hurt. The first time I though maybe he slept on it weird, and the 2nd time I thought coincidence, but today was the 3rd time and it seems very strange. Could this be neurological, or maybe a vitamin or mineral deficiency?