Crowe Melissa J, Meehan Michael T, Jones Rhondda E
College of Medicine and Dentistry, James Cook University, Townsville, QLD 4811, Australia.
Tropical Australian Academic Health Centre, Townsville, QLD 4811, Australia.
Medicina (Kaunas). 2025 Jun 19;61(6):1111. doi: 10.3390/medicina61061111.
: Military capability may be reduced in hot environments with individuals at risk of exertional heat stroke (EHS). Heat tolerance testing (HTT) can be used to indicate readiness to return to duty following EHS. HTT traditionally relies on rectal core temperature (T) assessment via a rectal probe. This study investigated the use of gastrointestinal core temperature (T) as an alternative to T during HTT. A secondary aim was to compare physiological factors between heat-tolerant and heat-intolerant trials. : Australian Defence Force personnel undergoing HTT following known or suspected heat stroke volunteered ( = 23 cases participating in 26 trials) along with 14 controls with no known heat illness history. Confusion matrices enabled comparison of HTT outcome based on T and T. The validity of T compared to T during HTT was assessed using correlation and bias. Comparisons between heat-tolerant and intolerant trials were performed using non-parametric tests. : Although T correlated closely with T (Spearman's rank correlation ρ = 0.893; median bias 0.2 °C) there was no consistent pattern in the differences between measures. Importantly, the two measures only agreed on heat tolerance outcome in 80% of trials with T failing to detect heat intolerance identified by T in 6 of 8 trials. If T was relied upon for diagnostic outcome, return to duty may occur before full recovery. None of the assessed covariates were related to the difference between T and T. In addition, resting heart rate and systolic blood pressure were significantly lower and body surface area to mass ratio significantly higher in heat-tolerant compared to intolerant trials. : It is not recommended to rely on T instead of T during HTT. Resting heart rate and systolic blood pressure findings point to the importance of aerobic exercise in conveying heat tolerance along with body composition.
在炎热环境中，个体有发生劳力性热射病（EHS）的风险，军事能力可能会降低。热耐受测试（HTT）可用于指示EHS后恢复执勤的准备情况。传统上，HTT依赖于通过直肠探头评估直肠核心温度（T）。本研究调查了在HTT期间使用胃肠道核心温度（T）替代T的情况。第二个目的是比较耐热和不耐热试验之间的生理因素。：已知或疑似中暑后接受HTT的澳大利亚国防军人员自愿参与（23例参与26次试验），另有14名无已知热病史的对照人员。混淆矩阵能够基于T和T比较HTT结果。使用相关性和偏差评估HTT期间T与T相比的有效性。使用非参数检验对耐热和不耐热试验进行比较。：尽管T与T密切相关（Spearman等级相关性ρ = 0.893；中位数偏差0.2°C），但测量值之间的差异没有一致的模式。重要的是，在80%的试验中，这两种测量方法仅在热耐受结果上一致，在8次试验中的6次试验中，T未能检测到T所确定的热不耐受。如果依赖T进行诊断结果，可能在完全康复之前就恢复执勤。评估的协变量均与T和T之间的差异无关。此外，与不耐热试验相比，耐热试验中的静息心率和收缩压显著更低，体表面积与质量比显著更高。：不建议在HTT期间依赖T而不是T。静息心率和收缩压的研究结果表明有氧运动以及身体成分在传递热耐受性方面的重要性。
