- vol.5, no.1, pp.31-38, 2000-02-25
The present study was carried out to examine the hypothesis that ocular surface temperature measured at the site over the iris by an infrared radiation thermometer could be an indication of core body temperature. In healthy young subjects, ocular surface (T_<os>), tympanic(T_<ty>), esophageal(T_<es>), mean skin(T^-_<sk>) temperatures, and local sweating rates and skin temperature of the forehead(T_<sf>) were measured in a chamber controlled at a moderate climate of 28℃-40%(rh) on two separate tests, a passive body warming and an exercise. The passive body warming was induced by immersion of lower limbs in hot water bath regulated 43℃. The moderate exercise was performed with cycle ergometer at the intensity of 80 W. In both tests, T_<os> didn't follow either core (T_<ty>, T_<es>) or shell (T^-_<sk>, T_<sf>) body temperatures. In the second series of experiments, ambient temperature (T_<am>) was raised from 27℃ to 34℃, or lowered from 34℃ to 27℃ for 10 min. In both tests, T_<os> followed the change of (T_<am>) rapidly in spite of the steady T_<ty>, and the change rates of T_<os> were greater than of T_<sf>. When T_<am> was raised slowly from 20℃ to 23℃ for 20 min, the T_<os> rise was almost simultaneous with the T_<am> rise, and there was a high correlation between these two factors (r=0.99). Moreover, the regional thermograms around eyes showed that skin temperature surrounding eyes was significantly higher than T_<os> (p<0.01). These results suggest that ocular surface temperature measured by an infrared radiation thermometer might reflect corneal temperature rather than iris temperature, and could not be an indication of core temperature.