Individual Responses to Heat Stress: Implications for Hyperthermia and Physical Work Capacity

Area of Science:

• Occupational Health
• Environmental Physiology
• Human Factors Engineering

Background:

• Extreme heat events are increasing, posing risks to occupational health and productivity.
• Existing reviews lack comprehensive analysis of individual factors influencing heat stress vulnerability.
• Understanding these factors is crucial for mitigating hyperthermia and work capacity loss.

Purpose of the Study:

• To review the impact of individual characteristics on human heat stress response.
• To analyze the relationship between individual factors, hyperthermia risk, and productivity loss in hot environments.
• To provide practical guidance for industrial hygienists.

Main Methods:

• Narrative review of scientific literature.
• Analysis of factors including body mass, fitness, heat adaptation, aging, sex, and health conditions.
• Consideration of work type, intensity, and climate conditions.

Main Results:

• Heat adaptation, high aerobic fitness, and large body mass are protective against heat stress.
• Low fitness, low body mass, and lack of heat adaptation are detrimental.
• Factors like aging, sex, and diabetes have smaller independent effects in matched individuals.

Conclusions:

• Individual factors critically influence occupational heat stress responses.
• Understanding these dynamics is essential for predicting heat wave impacts.
• Recommendations can help reduce hyperthermia risk and productivity losses in hot workplaces.