Be wary of the limitations of correlating a temperature with infection in the elderly: 1. The elderly are 3-4x more likely to develop hypothermia in response to serious infections. Never rule out a serious infection simply based on a low or normal body temperature. 2. The elderly take longer to mount a fever than younger patients. 3. The elderly have a slightly lower body temperature at baseline, possibly 1 degree lower. As a result, "fever" in the elderly is sometimes defined as 99.5 degrees rather than the traditional 100 or 100.4 used in younger patients.
