[Validation of axillary temperature measurement as a biorhythm marker. Study of the sex variable]

This paper analyses the relationship between oral and axillary temperatures in the waking part of the day, and verify the existence of sex differences within both parameters. We selected 20 healthy subjects (10 men and 10 women) aged 22 to 30, controlling environmental and subject variables. The women's group does show greater thermic values for axillary temperature (8 of the 13 recordings). There was a highly correlation between sex groups (r = 0.854, p less than 0.001), axillary temperature rhythms between sexes are coupled and any differences are only of degree. For oral temperature the women's group showed higher values in 3 recordings (15.00, 18.00 and 21.00), and there was no correlation between men and women throughout the day. These results evidence sex differences in rhythmic patterns of oral temperature. Correlations between temperatures were highly positive for the whole sample, men and women. Our study presents empirical data on the validity of using axillary temperature as alternative measurement of body temperature. We expect the use of axillary temperature to be increasingly employed in chronobiological field studies.