Hibernation is a unique evolutionary adaptation to conserve energy. During the pre-hibernation (i.e. fall) season, a progressive decline in core body temperature and further decrease in metabolism underlie a seasonal modulation in thermoregulation. The onset of hibernation requires marked changes in thermoregulatory attributes including adjustment in body temperature and tissue specific increases in thermogenic capacity. The hibernation season is characterized by a regulated suppression in thermogenesis allowing the onset of torpor interrupted by periodic activation of thermogenesis to sustain interbout arousals. Thyroid hormones are known to regulate both body temperature and metabolism, and for this reason, the hypothalamic-pituitary-thyroid axis and thyroid hormones have been investigated as modulators of thermogenesis in the phenomenon of hibernation, but the mechanisms remain poorly understood. In this review, we present an overview of what is known about the thermogenic roles of thyroid hormones in hibernating species across seasons and within the hibernating season (torpor-interbout arousal cycle). Overall, the hypothalamic-pituitary-thyroid axis and thyroid hormones play a role in the pre-hibernation season to enhance thermogenic capacity. During hibernation, thermogenesis is attenuated at the level of sympathetic premotor neurons within the raphe pallidus and by deiodinase expression in the hypothalamus. Further, as recent work highlights the direct effect of thyroid hormones within the central nervous system in activating thermogenesis, we speculate how similar mechanisms may occur in hibernating species to modulate thermogenesis across seasons and to sustain interbout arousals. However, further experiments are needed to elucidate the role of thyroid hormones in hibernation, moving towards the understanding that thyroid hormones metabolism, transport and availability within tissues may be the most telling indicator of thyroid status.

冬眠是一种独特的进化适应以节约能源。在冬眠前（即秋季）季节，核心体温的逐渐下降和新陈代谢的进一步下降是体温调节季节性调节的基础。冬眠的开始需要体温调节属性的显着变化，包括体温的调整和生热能力的组织特异性增加。冬眠季节的特点是产热受调节抑制，允许产热的周期性激活中断麻木的开始，以维持发作间的觉醒。众所周知，甲状腺激素可以调节体温和新陈代谢，因此，下丘脑-垂体-甲状腺轴和甲状腺激素已被研究作为冬眠现象中产热的调节剂，但其机制仍知之甚少。在这篇综述中，我们概述了甲状腺激素在跨季节和冬眠季节（麻木-间歇性觉醒循环）内的冬眠物种中的产热作用。总体而言，下丘脑-垂体-甲状腺轴和甲状腺激素在冬眠前的季节发挥作用，以增强产热能力。在冬眠期间，产热在苍白中缝内的交感前运动神经元水平和下丘脑中的脱碘酶表达减弱。此外，由于最近的工作强调了中枢神经系统内甲状腺激素在激活产热方面的直接作用，我们推测，在冬眠物种中可能会发生类似的机制，以调节跨季节的产热并维持间歇性唤醒。然而，还需要进一步的实验来阐明甲状腺激素在冬眠中的作用，进一步了解甲状腺激素的代谢、运输和组织内的可用性可能是甲状腺状态最有说服力的指标。