Abstract
During hibernation animals oscillate from near ambient (T(a)) to euthermic body temperatures (T(b)). As animals arouse, the rate of rewarming (RRW) might be expected to simply increase as a function of time. We monitored the T(b) of golden-mantled ground squirrels (Spermophilus lateralis) housed at 4, 8, 12, and 16 degrees C during natural arousals. The maximum RRW, the time required to reach a maximum RRW, and the relative time index all demonstrated negative relationships with T(a). The T(b) corresponding to maximal RRW demonstrated a positive relationship with T(a). Squirrels reached maximal RRW when they had generated 30 to 40% of the heat required to reach a euthermic T(b). These data suggest that arousal is more constrained than expected and that both time and temperature influence the RRW.