Can you have surgery if your temperature is 99-99.5? no other symptoms, just an off and on a slight rise in temperature?

Key is whether this is a normal variation peak for you, an inaccurate digital thermometer, or a sign of fever of unknown origin. Let your surgeon know about this and get a pre-operative full physical exam by an internist. The borderline elevation may be of little consequence, but why take a risk.

For elective surgery a patient with low grade fever usually has to have a preoperative consultation by a physician or specialist in internal medicine to determine the cause of the fevers and to determine whether the surgeon should proceed with the elective procedure or cancel it. Rarely we OK minor surgery in such patients without infection but more often we recommend cancelling or delaying it.