Short-Term Heat Acclimation Protocols

The intervention was any form of short-term heat acclimation that were equal to or longer than four [13 (link)], but no more than twelve HA days, as this is the latest time that a heatwave can be accurately predicted via a weather report [11 (link)]. The specific outcome measures being assessed were those conducive to generating heat adaptive responses that can be considered desirable for protection against heat waves either being physiological such as any cardiovascular measures or psychological e.g., reduced perception of fatigue [20 (link)]. The final articles were reviewed to assess if any adverse events were reported, this is in the interest of feasibility and safety for future protocols. No restrictions on the timeframe of publication were implemented and only peer-reviewed studies using primary empirical data were eligible.
All included studies were assessed for methodologic quality and risk of bias. The included studies were subject to a modified Downs and Black (1998) checklist to assess the overall quality of the papers and rank them accordingly [36 (link)–38 (link)]. The modified checklist uses an altered scoring system for item 27 that refers to the power of the study [37 (link)–39 (link)]. Accordingly, the maximum score for item 27 was reduced from five to one thus the highest possible score for the checklist was twenty-seven. Downs and Black (1998) score ranges were given corresponding quality levels as previously reported [37 (link)]: excellent (26–28); good (20–25); fair (15–19); and poor (<14).