Fig. 4.

Body temperature (°C) in PD2 and PD8 rats exposed to acute hypoxia. One pup from each litter was instrumented with a microprobe rectal thermometer and allowed to huddle with its littermates. Body temperature was monitored continuously during the entire hypoxic exposure, and data were recorded every 15 min; n = 4 or 5 instrumented pups per age group per exposure (21% O₂ or 8% O₂ for 4 h). Body temperature significantly decreased from baseline values after 30 min at 8% O₂, and values at 240 min were significantly lower than those at 30 min (PD2 and PD8; P < 0.05). Exposure to 21% O₂ for 4 h had no effect on body temperature in pups at either age (P > 0.05).