Fig. 5. Effect of methodology on T_b of lizards when exposed to hypoxia. The `preferred' T_b of nine bearded dragons was determined at 4% and 21% oxygen in an extreme temperatures shuttle box, a thermal gradient and an electronically operated temperature shuttle box (ramping shuttle box). Values are means of nine lizards' median T_b values ±s.d.^*Significant difference between the extreme temperature trials and the other trials. Significant effect of 4% O₂ on T_b within a trial.