Question from Chicopee, Massachusetts, USA:

My daughter was released from the hospital after treatment for an undetermined infection which has been identified as possible influenza or another viral flu-like illness. She took six liters of fluid in the Emergency Room and was on a slow drip after hospital admission for 36 hours. Urine and blood tests and cultures were all negative for bacterial infections. A chest x-ray was also negative. That evening, she was released to go home. Her temperature dropped to 96.3 degrees F. and she was sweating profusely having to change sheets and clothing three times in less than eight hours. The next night (at the same time, 3 a.m.), her temperature registered at 96.7 degrees F. The pediatrician says it is due to the fever breaking, but it has not been that low, ever, and, now, at other times over the past two days, it is lower than normal (98.1 degrees F., 97.9 degrees F.) and we are concerned that is not due to fever breaking since her last elevated fever was the night prior to the first low register and it was only 99.9 degrees F. What else could cause a low body temperature? Should we be concerned?