Human cold exposure, adaptation, and performance in high latitude environments

Abstract

Cold exposure is present to significant amounts in the everyday occupational and leisure time activities of circumpolar residents. A cross-sectional population study demonstrated that Finns reported being exposed to cold on average 4% of their total time. Factors modifying cold exposure are: age, gender, employment, education, health, and amount of physical exercise. Several symptoms and complaints are associated with wintertime cold exposure and start to appear more commonly when temperatures decrease below -10 degrees C. Urban circumpolar people do not evidently demonstrate cold acclimatization responses in terms of changes in thermoregulation, probably due to behavioral factors (adequate protective clothing, short cold exposures, and high housing temperatures). With regard to performance, we observed that moderate cold exposure, which may occur in everyday life, affects cognition negatively through the mechanisms of distraction and both positively and negatively through the mechanism of arousal (increased vigilance). It seems that especially simple cognitive tasks are adversely affected by cold, while in more complex tasks performance may even improve in mild or moderate cold. Repeated, short cold exposures in the laboratory, causing cold habituation responses, do not markedly improve neuromuscular or cognitive performance. The article discusses the functional significance of cold exposure, adaptation, and the specific environmental conditions and physiological mechanisms that affect behavior and performance in high latitude environments.

The effect of Antarctic residence on energy dynamics and aerobic fitness

“…A full review of the issue of cold adaptation is beyond the scope of this article and the reader is referred to in-depth reviews of the subject, such as that of Mäkinen (53).…”

XP-Antarctik Expedition: The Effect of a Month-Long Expedition in Antarctica on Physiological Performance

“…Thus, the impaired power and force production of cooled muscles may be due to changes in their neuromuscular function that can decrease performance and increase injury risks (Mäkinen, 2007). Furthermore, the muscular performance decreases during dynamic exercises, especially during fast contraction velocities (Oksa et al, 2004).…”

“…As well, muscle performance decreases when exposed to cold, even for a single short exposure time (Stocks et al, 2004). Thus, cold exposure decreases maximal strength, muscular endurance, and cardiovascular performance, and significantly increases the metabolic cost of physical activities (Mäkinen, 2007;Oska et al, 2004;Stocks et al, 2004). However, this deterioration can be minimized by an appropriate initial preparation and caloric intake equal to the energy uptake during the expedition.…”

Thyroid hyperactivity with high thyroglobulin in serum despite sufficient iodine intake in chronic cold adaptation in an Arctic Inuit hunter population

“…Field studies on cold adaptation in man are hampered by man's behavioural adaptations to cold (23). Human cold exposure increased thyroidal iodide turnover in an environmental chamber study (24) and plasma clearance rate of T 3 in Antarctic expeditioners (25).…”