Background: Many research studies require recruiting heat-acclimatized workers to participate in heat-stress experiments and application fields. A reliable heat acclimatization program for workers in countries with hot environments has not been reported yet.
Objective: The objective of this study was to estimate the effects of heat stress and the amount of acclimatization required in hot-climate countries.
Methods: Eighteen male workers from an industrial population participated in this experiment. Nine days of exposure to a hot environment (wet-bulb globe temperature, 30°C) was the independent variable. The participants' cardiac costs and increment aural-canal temperatures were the dependent variables.
Results: The study results revealed that 5 days of exposure to heat sessions were sufficient to heat acclimatize the workers based on their physiological responses (i.e., heart rate and aural-canal temperature).
Conclusions: According to the available literature, workers in hot climate countries, similar to the study cohort, can heat acclimatize faster than those in other Western countries.
Keywords: Heat stress; cardiac cost; heat strain; hot climate; thermal environments; wet-bulb globe temperature.