Should Workers Avoid Consumption of Chilled Fluids in a Hot and Humid Climate?

Area of Science:

• Occupational Health
• Environmental Physiology
• Sports Science

Background:

• Drinking water is a common method for preventing occupational heat stress.
• Workers are often advised to consume tepid fluids for rehydration, believing chilled beverages delay absorption.
• This advice may stem from a misunderstanding of gastric emptying and fluid absorption dynamics.

Purpose of the Study:

• To clarify the impact of fluid temperature on rehydration and gastric emptying in occupational settings.
• To evaluate the evidence behind advising workers to avoid chilled beverages.
• To provide evidence-based hydration messaging for workers in hot and humid climates.

Main Methods:

• Review of factors influencing gastric emptying, including fluid temperature, volume, and energy density.
• Analysis of the physiological effects of fluid temperature on gastric emptying and core body temperature.
• Consideration of worker preferences and consumption patterns regarding fluid temperature.

Main Results:

• The impact of fluid temperature on gastric emptying is modest and short-lived due to physiological warming.
• Chilled beverages are preferred by workers and lead to greater consumption, promoting gastric emptying via increased gastric volume.
• Current advice to avoid cool/cold fluids appears to be a misinterpretation of scientific evidence.

Conclusions:

• Hydration messaging should encourage the consumption of chilled beverages, highlighting their thermal benefits in hot conditions.
• Promoting worker autonomy in choosing preferred fluid temperatures can improve hydration status.
• Optimizing fluid consumption through palatability is key for effective rehydration and heat stress prevention.