Hi. My boyfriend has had the following symptoms maybe 3 or 4 times in the span of about a month or a little more. He gets cold, shivers violently, has a headache, a fever, and feels like throwing up. Sometimes he gets one or two of the symptoms, sometimes all, but it keeps coming back. What's wrong with him? He is 16, about 140 pounds, 5'8". He's only had some minor sports injuries.