Human physiological responses of exposure to extremely cold environments

Area of Science:

• Environmental Physiology
• Human Health and Safety

Background:

• Increasing frequency of extreme cold events necessitates understanding human physiological responses.
• Cold exposure can lead to significant health and safety risks, including cold stress and injury.

Purpose of the Study:

• To investigate human physiological responses during exposure to extremely cold environments.
• To identify critical physiological parameters for assessing cold strain and injury risk.
• To evaluate the impact of initial cold exposure on cognitive and physical performance.

Main Methods:

• 12 subjects were exposed to controlled cold environments (-5°C, -10°C, -15°C) in a climate chamber.
• Key physiological parameters including core and skin temperature, blood pressure, heart rate, respiration rate, and blood oxygen saturation were monitored.
• Short-term responses to temperature changes were specifically analyzed.

Main Results:

• Local skin temperature and blood pressure emerged as significant indicators of cold strain risk.
• Finger temperature below -5°C for over 20 minutes is critical for hand flexibility, risking injury and reduced manual performance.
• Initial physiological strain significantly impairs judgment and action, highlighting the need for acclimatization.

Conclusions:

• Local skin temperature and blood pressure are vital for assessing cold strain.
• Maintaining finger temperature is essential for manual dexterity and preventing injury in extreme cold.
• A 3-minute adaptation period in cold environments is recommended to stabilize physiological parameters and enhance safety and performance.