Fig. 6. Body surface temperature minus tongue temperature at 21, 10 and 6% O₂ between ambient temperatures of 32–38°C. There was a significant effect of oxygen and ambient temperature on this difference (two-way repeated-measures ANOVA), suggesting that hypoxic conditions led to a higher value at lower ambient temperatures. The dotted line represents an extrapolation beyond 38°C in the 6% O₂ group.