The effect of face fanning during recovery from exercise hyperthermia

Hyperthermia was induced in nine subjects on two separate occasions by a progressive treadmill run, which resulted in an average esophageal temperature (Tes) of 39.77 +/- 0.07 degree C after 30-57 min. Fanning the face during exercise to simulate conditions during running (wind at 3.75 m X s-1) maintained a tympanic temperature (Tty) that was lower than Tes; the difference was 1.5 degrees C at the end of exercise. In one session, face fanning was interrupted at the end of running, whereas in the other it was maintained for 15 min after exercise stopped. Face fanning had no significant influence on the fall of Tes during recovery, but it markedly influenced the course of Tty during this period. When face fanning was stopped at the end of the run, Tty rose by nearly 0.5 degree C, peaked after 4.5 min, and thereafter decreased slowly to a value close to Tes. In contrast, when face fanning was maintained throughout the recovery period, Tty rose only slightly (0.1 degree C) and remained significantly lower than Tes at all times. The results suggest that following hyperthermic exercise, face fanning could be helpful in preventing acute cerebral hyperthermia.