Fig 1.
Core temperature changes in rats pre-warmed to 40°C (PW40, n = 17), 1% above baseline temperature (PW1%, n = 17) or without warming (NW, n = 17).
Time spent in warming chamber is highlighted in red (time -35 to 0 mins), followed by induction of general anesthesia and removal from warming chamber (green box, time 0 to 50 mins). Area under the curve during temperature reduction was calculated from time 0 to 50 mins. Before time 0, data are plotted every 5 minutes for clarity. Data presented as mean ± SEM.
Fig 2.
Time to reach individual hypothermia threshold.
The no-warming (NW, n = 17) group reached their individual hypothermia threshold more quickly than the pre-warming to 1% above baseline core temperature (PW1%, n = 17) (p < 0.01) and pre-warming to 40°C (PW40, n = 17) (p < 0.0001) groups. The PW1% group reached their individual hypothermia threshold more quickly than the PW40 group (p < 0.01). Data presented as mean ± SEM. **p < 0.01. ****p < 0.0001.
Fig 3.
Bland-Altman plot of repeated measures comparing rectal and core temperatures.
Rectal temperature underestimates core temperatures by 0.20°C, with 95% limits of agreement ranging from -4.3 to 4.0. Data were pooled from the three treatment groups.
Fig 4.
Bland-Altman plot of repeated measures comping fur and core temperatures.
Fur temperature underestimates core temperature by 2.50°C, with 95% limits of agreement ranging from -6.7 to 1.7. Data were pooled from the three treatment groups.
Fig 5.
Bland-Altman plot of repeated measures comparing tail and core temperatures.
Tail temperature underestimates core temperature by -7.80°C, with 95% limits of agreement ranging from -15.3 to -0.3. Data were pooled from the three treatment groups.
Fig 6.
Percentage of time rats faced the heat source.
The no-warming (NW, n = 17) group spent approximately 50% of the time facing the heat source and this was significantly longer than the pre-warming to 1% above baseline core temperature (PW1%, n = 17) and pre-warming to 40°C (PW40, n = 17) groups during the first and last 3 mins of observation (p < 0.05). During the first three minutes, the PW40 group was more likely to face the heat source than PW1% (p < 0.05). Data presented as median ± 10–90 percentile. *p < 0.05. **p < 0.01. ***p < 0.001.