Fever on and off first Widal negative and after Widal done after 10 days O& H  1:160 taken antibiotics then Widal O&H is 1:40 but still fever morning up to 9am it is below 98.6 and after 11am it is increasing to 99 and at afternoon it is going to 99.6 and at evening at 8pm it is coming to normal during this I am having headache ,fever ,from 40 days .Thyroid normal ,bp normal,some doctors md (gen med) saying that in summer take 100 as fever 99.6 is not fever ,during every day I am having low grade fever and headache ,10 days back esr is 26 ,give ur kind information sir it  may help to me