Body temperature is an important physiological parameter in many studies of laboratory mice. Continuous assessment of body temperature has traditionally required surgical implantation of a telemeter, but this invasive procedure adversely impacts animal welfare. Near-infrared thermography provides a non-invasive alternative by continuously measuring the highest temperature on the outside of the body (T_skin), but the reliability of these recordings as a proxy for continuous core body temperature (T_core) measurements has not been assessed. Here, T_core (30 s resolution) and T_skin (1 s resolution) were continuously measured for three days in mice exposed to ad libitum and restricted feeding conditions. We subsequently developed an algorithm that optimised the reliability of a T_skin-derived estimate of T_core. This identified the average of the maximum T_skin per minute over a 30-min interval as the optimal way to estimate T_core. Subsequent validation analyses did however demonstrate that this T_skin-derived proxy did not provide a reliable estimate of the absolute T_core due to the high between-animal variability in the relationship between T_skin and T_core. Conversely, validation showed that T_skin-derived estimates of T_core reliably describe temporal patterns in physiologically-relevant T_core changes and provide an excellent measure to perform within-animal comparisons of relative changes in T_core.

在许多实验室小鼠研究中，体温是重要的生理参数。传统上，连续评估体温需要手术植入遥测仪，但是这种侵入性手术会对动物福利产生不利影响。近红外热成像通过连续测量人体外部（T_皮肤）的最高温度提供了一种非侵入性替代方法，但是这些记录作为连续核心体温（T _core）测量指标的可靠性尚未得到评估。 。在这里，T_核心（30 s分辨率）和T_皮肤在随意接触和限制性喂养条件下的小鼠中连续三天（1 s分辨率）进行测量。随后，我们开发了一种算法，该算法优化了T_皮肤派生的T_核估计的可靠性。这将30分钟间隔内每分钟最大T_皮肤的平均值确定为估算T _core的最佳方法。然而，随后的验证分析确实表明，由于T_皮肤与T_核心之间的关系在动物之间存在很高的变异性，因此这种T_皮肤衍生的代理无法提供绝对T_核心的可靠估计。相反，验证显示T_皮肤T_核的估计值可靠地描述了与生理相关的T_核变化中的时间模式，并为进行T_核相对变化的动物内比较提供了极好的方法。