This happened 5-6 times in last 2 yrs - sudden onset of high fever (101-103) with chills/headache/body ache, fever broke on day 2, resume normal on day 3, no other symptoms. it appears self-limiting but happens more often. i cannot find a trigger or cyc

Any relation to food: Charcot's intermittent fever can do this. It is caused by migration of a gall stone into the bile duct and then popping out again. See your doc.

Need to examine: It is not feasible to provide a meaningful opinion without additional history, physical examination and may be some tests. It would be prudent to see your doctor. Wish you good health!