Peripheral responses to cold: case studies from an Arctic expedition

Area of Science:

• Physiology
• Environmental Medicine
• Arctic Exploration

Background:

• Peripheral acclimatization is crucial for cold environments.
• Arctic conditions present risks of cold injury and impact physiological adaptations.
• Understanding cold injury and acclimatization interactions is vital for explorer safety.

Purpose of the Study:

• To investigate peripheral acclimatization in Arctic explorers.
• To examine the effects of cold injury on acclimatization processes.
• To assess physiological responses during a prolonged Arctic expedition.

Main Methods:

• Measured extremity digit temperatures during cold-water immersion (4°C) before and after a 109-day Arctic ski trek.
• Monitored two explorers undertaking a self-supported trek with heavy loads (backpacks up to 45 kg, sleds ~100 kg).
• Assessed environmental conditions, including average air temperature of -21°C.

Main Results:

• Explorers developed moderate trench foot but no frostbite.
• Post-expedition, both explorers showed reduced mean finger temperatures during cold-water immersion, indicating impaired hand acclimatization.
• Toe temperatures increased post-expedition in most feet, suggesting some acclimatization occurred despite trench foot.

Conclusions:

• Prolonged heavy load carriage may impede hand blood flow and nerve function, inhibiting acclimatization.
• Peripheral acclimatization can still occur even after experiencing and resolving cold injuries like trench foot.
• Findings highlight the complex interplay between cold injury, load carriage, and physiological adaptation in extreme environments.