Evaluation of core and surface body temperatures, prevalence, onset, duration and severity of hot flashes in men after bilateral orchidectomy for prostate cancer.

OBJECTIVE To assess the prevalence, onset, duration and severity of hot flashes in men after bilateral orchidectomy (BO) for prostate cancer, to evaluate body temperature changes during hot flashes and to determine whether an elevated temperature within a few days after BO can be caused by deprivation of androgen. MATERIALS AND METHODS Patients (n = 101) were questioned about the characteristics of their hot flashes after BO for prostate cancer. A subgroup of these men (n = 17) were instructed to record their oral and forehead temperatures during and at fixed intervals between hot flashes daily for 4 weeks. RESULTS The mean age was 71.6 years, mean follow-up after BO was 33.2 months. Hot flashes were reported by 87 men (86%) with previous spontaneous remission in 9 (10%). The median time between BO and the onset of hot flashes was 21 days (range 1-730), median number of hot flashes 3 per day (range 1-20), and median duration was 120 seconds (range 5 to 1800). There was no significant difference between median oral (36.4(o) C) and forehead (36.0(o) C) temperature in the normal state, but during hot flashes the median forehead temperature (37.0(o) C) was higher than the oral temperature (36.5(o) C) (p = 0.0004). Both median oral and forehead temperatures were higher during hot flashes (36.5(o) C and 37.0(o) C) than in the normal state (36.4(o) C and 36.0(o) C, respectively) (p < 0.0001). During hot flashes, the oral temperature was 38(o) C to 40(o) C in only 3.2% of 593 readings in 17 patients. CONCLUSIONS The median oral and forehead temperatures are higher during hot flashes than in normal periods. Oral temperature elevation > 38(o) C within days after a BO is unlikely to be the result of androgen deprivation alone.