Thoroughbred racehorses perform exercise at maximal intensities and typically display a hyperthermic exercise response, which can drive core body temperature to critical levels. Despite extremely efficient thermoregulatory mechanisms, certain weather conditions may affect the horse’s ability to cool and result in a syndrome referred to as exertional heat illness (EHI). This is characterised by central nervous system dysfunction, as well as cytotoxic effects of heat on cells, which can produce deleterious consequences. Early detection of exertional heat illness (EHI) in Thoroughbred racehorses can be difficult because signs are often vague and the measurement of rectal temperature as an indicator of hyperthermia is not practical. Best practice in the treatment of EHI in horses, as in human subjects, centres on early detection, rapid assessment and aggressive cooling. Research in human subjects has shown that EHI is manageable when recognised early and appropriate treatment provided. The aim of this study was to investigate the measurement of skin surface temperature (SST) by an infrared thermometer as an aid in the early detection of EHI. A skin surface temperature ≥39°C in the immediate postrace period is considered to be hot. It reflects the interaction of exercise‐related metabolic heat production, physiological adjustments to the skin surface such as vasodilation and sweating, together with the effect of high ambient temperature. Most importantly, high SST is associated with a reduced core‐to‐skin temperature difference, which retards heat transfer from the deep body tissues to the skin and can hinder heat dissipation. Identification of horses with high SSTs can prioritise them for rapid cooling and curtail possible progression to EHI.

中文翻译：

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手持式红外测温仪作为纯种赛马劳累性热病的早期发现工具的使用：澳大利亚东部赛马场的一项研究

纯种赛马以最大强度进行锻炼，并且通常会表现出体温过高的运动反应，这可能会使核心体温升高到临界水平。尽管温度调节机制非常有效，但某些天气条件可能会影响马的降温能力，并导致一种称为劳累性热病（EHI）的综合症。其特征是中枢神经系统功能障碍，以及热量对细胞的细胞毒性作用，会产生有害的后果。在纯种赛马中尽早发现劳累性热病（EHI）可能很困难，因为体征常常模糊不清，而测量直肠温度作为体温过高的指标是不切实际的。与人类受试者一样，治疗马EHI的最佳做法集中在早期发现，快速评估和积极降温。对人类受试者的研究表明，尽早发现EHI并提供适当的治疗方法，EHI是可以控制的。这项研究的目的是研究通过红外测温仪对皮肤表面温度（SST）的测量，以帮助早期检测EHI。赛后不久的皮肤表面温度≥39°C被认为很热。它反映了与运动有关的代谢热产生，对皮肤表面的生理调节（如血管舒张和出汗）以及高环境温度的影响之间的相互作用。最重要的是，较高的SST会降低核心与皮肤之间的温度差，从而阻碍热量从深层组织传递到皮肤并阻碍散热。