Hi, my son is almost 7. He only weighs about 45lbs. He has came down with a low grade fever.(100.2), complaining of his legs hurting/aching when he walks and hes extremely tired with no appetite. My other 2 kids were sick last week,one with what im told was a virus with a horendous sore throat,the other with fever,no appetite x4 days and ear infection. Im not sure what this one can be.