Why am I getting low grade fever in the evenings?

From the last 15 days I am having low grade fever of 99.2 F. In the morning my temperature is normal (98 degree F) but by the evening, after returning from office, it is 99.2 degree F and later in the night it is again normal. My blood report is normal. There are no symptoms of typhoid or any other infection. I am also having pain in my legs. I am an engineer and have to do a lot of physical work.

 

It is known that the temperature of a healthy person can vary during the day as part of the body's circadian rhythm and there is no cause for worry. Obviously a stressful job can cause tiredness and aching and maybe the stretched muscles cause products in the body that raise the temperature. The only serious worry about a fever is if there is an infection such as tuberculosis or brucellosis, but these diseases can be diagnosed by your physician.