Suggest Treatment For Leg Pain And Low Grade Fever

My husband began having leg pain, then severe shaking like chills, low grade fever if any, what could this be? He has had malaria before so said it felt like a relapse except for the severe leg pain that started at his right calf and moved into his groin area. Then he complained of similar symptoms in his upper arm. He took two aspirin in case it was a clot or something. Within about a half an hour he began to shake like he had the chills, I think they call this the rigors, and could not control them. He has finally quit as he has gone to sleep and is snoring. Any ideas as to what this could be? Does it sound like a malaria relapse? His foot has been tender for several days for which he has been taking a lot of naproxin sodium (advil). Update : Now his chills have subsided some but his fever is getting higher. We lived in Nicaragua for 3.5 years helping with an orphanage and building houses for the poor. He got a bad case of