Peripheral responses to cold: case studies from an Arctic expedition.
OBJECTIVE
An Arctic expedition provided an opportunity to examine the interaction between cold injury and peripheral acclimatization. The conditions were similar to those during which acclimatization has been demonstrated, yet they were also conducive to development of peripheral cold injury.


METHODS
Extremity digit temperatures were measured during 30-minute peripheral cold-water (4 degrees C) immersion (CWI) in 2 explorers (R.G. and T.L.) before and after a 109-day Arctic ski trek (average T(air) = -21 degrees C). This self-supported trek involved carrying heavy backpacks (up to 45 kg) and hauling sleds (approximately 100 kg).


RESULTS
During the expedition, the explorers' hands did not sustain frostbite, but their feet developed moderate trench foot. Unexpectedly, both men exhibited lower mean finger temperatures during CWI after the expedition in right and left hands (R.G. by 0.9 degrees C and 0.2 degrees C; T.L. by 1.8 degrees C and 1.1 degrees C), suggesting peripheral acclimatization was impaired. In contrast, mean toe temperatures during CWI were warmer in both right and left feet for T.L. (by 3.6 degrees C and 2.3 degrees C) and in the left foot for R.G. (by 1.3 degrees C) postexpedition. There was no change in R.G.'s right toe mean temperature.


CONCLUSIONS
We speculate that prolonged heavy load carriage may have impaired blood flow or nerve conduction in the hands and inhibited acclimatization. Our data also suggest that despite incidence of moderate trench foot, acclimatization can still occur after resolving this injury.
O'Brien
Catherine
C
Thermal and Mountain Medicine Division, US Army Research Institute of Environmental Medicine, Natick, MA 01760-5007, USA. catherine.o'brien@na.amedd.army.mil
Frykman
Peter N
PN
D000064:Acclimatization; D000328:Adult; D001110:Arctic Regions; D001775:Blood Circulation; D001831:Body Temperature; D001833:Body Temperature Regulation; D003080:Cold Temperature; D005101:Expeditions; D005385:Fingers / Q000098:blood supply* / Q000502:physiology; D006801:Humans; D008297:Male; D009051:Mountaineering; D012039:Regional Blood Flow; D012881:Skin Temperature; D014034:Toes / Q000098:blood supply* / Q000502:physiology; D014664:Vasodilation