We read with interest the recent article by Waldron et al. [1] regarding the effects of heat acclimation and acclimatisation on maximal aerobic capacity in thermoneutral and hot environments. This topic is important to researchers and applied sports scientists, as there is debate as to whether heat-based training benefits subsequent aerobic performance in thermoneutral conditions [2]. As such, our focus is directed toward this research question and aspect of the original review. Waldron et al. [1] concluded that heat acclimation/acclimatisation (HA) had a small, positive effect on maximal aerobic capacity in thermoneutral environments (Hedges’ g = 0.30, 95% confidence interval 0.06–0.54). However, there are aspects of the meta-analysis that require further consideration. In the current article, we show how a more suitable analytical approach led to conclusions that are substantively different from those reported by Waldron et al.