Evaluating physiological strain during cold exposure using a new cold strain index

A cold strain index (CSI) based on core (T(core)) and mean skin temperatures (T(sk)) and capable of indicating cold strain in real time and analyzing existing databases has been developed. This index rates cold strain on a universal scale of 0-10 and is as follows: CSI = 6.67(T(core t) - T(core 0)). (35 - T(core 0))(-1) + 3.33(T(sk (t)) - T(sk 0)). (20 - T(sk 0))(-1), where T(core 0) and T(sk 0) are initial measurements and T(core t) and T(sk t) are simultaneous measurements taken at any time t; when T(core t) > T(core 0), then T(core t) - T(core 0) = 0. CSI was applied to three databases. The first database was obtained from nine men exposed to cold air (7 degrees C, 40% relative humidity) for 120 min during euhydration and two hypohydration conditions achieved by exercise-heat stress-induced sweating or by ingestion of furosemide 12 h before cold exposure. The second database was from eight men exposed to cold air (10 degrees C) immediately on completion of 61 days of strenuous outdoor military training, 48 h later, and after 109 days. The third database was from eight men repeatedly immersed in 20 degrees C water three times in 1 day and during control immersions. CSI significantly differentiated (P < 0.01) between the trials and individually categorized the strain of the subject for two of these three databases. This index has the potential to be widely accepted and used universally.

[1]  P Tikuisis,et al.  Exertional fatigue, sleep loss, and negative energy balance increase susceptibility to hypothermia. , 1998, Journal of applied physiology.

[2]  Scott J Montain,et al.  Evaluation of different levels of hydration using a new physiological strain index. , 1998, American journal of physiology. Regulatory, integrative and comparative physiology.

[3]  M. Sawka,et al.  Human thermoregulatory responses during serial cold-water immersions. , 1998, Journal of applied physiology.

[4]  K B Pandolf,et al.  A physiological strain index to evaluate heat stress. , 1998, American journal of physiology. Regulatory, integrative and comparative physiology.

[5]  M N Sawka,et al.  Hypohydration and thermoregulation in cold air. , 1998, Journal of applied physiology.

[6]  M. Sawka,et al.  Control of thermoregulatory sweating is altered by hydration level and exercise intensity. , 1995, Journal of applied physiology.

[7]  T. van der Werf,et al.  Effects of steady hypothermia and normothermia on the electrocardiogram in human poikilothermia. , 1991, Arctic Medical Research.

[8]  K B Pandolf,et al.  Thermoregulatory model for immersion of humans in cold water. , 1988, Journal of applied physiology.

[9]  Richard R. Gonzalez,et al.  Human performance physiology and environmental medicine at terrestrial extremes , 1988 .

[10]  K B Pandolf,et al.  Cooling different body surfaces during upper and lower body exercise. , 1987, Journal of applied physiology.

[11]  J. Bittel.  Heat debt as an index for cold adaptation in men. , 1987, Journal of applied physiology.

[12]  Bernard Drevillon,et al.  In situ spectroscopic ellipsometry study of the growth of microcrystalline silicon , 1986 .

[13]  K. Pandolf,et al.  Human Thermoregulatory Model for Immersion in Cold Water , 1986 .

[14]  K B Pandolf,et al.  Human thermoregulatory responses to cold air are altered by repeated cold water immersion. , 1986, Journal of applied physiology.

[15]  J. Frim,et al.  Effect of cold exposure on various sites of core temperature measurements. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[16]  G. Ferretti,et al.  Superficial shell insulation in resting and exercising men in cold water. , 1982, Journal of applied physiology: respiratory, environmental and exercise physiology.

[17]  E. Shvartz,et al.  Fluid shifts and endocrine responses during chair rest and water immersion in man. , 1980, Journal of applied physiology: respiratory, environmental and exercise physiology.

[18]  C Boutelier,et al.  Survival and Protection of Aircrew in the Event of Accidental Immersion in Cold Water , 1979 .

[19]  J. M. Hanna,et al.  Skinfolds and resting heat loss in cold air and water: temperature equivalence. , 1975, Journal of applied physiology.

[20]  D. M. Gates,et al.  THERMODYNAMIC EQUILIBRIA OF ANIMALS WITH ENVIRONMENT , 1969 .

[21]  B. Saltin,et al.  Esophageal, rectal, and muscle temperature during exercise. , 1966, Journal of applied physiology.

[22]  A. B. Craig,et al.  Thermal regulation during water immersion. , 1966, Journal of applied physiology.

[23]  S. K. Hong,et al.  Physical insulation of Korean diving women. , 1962, Journal of applied physiology.

[24]  F. Plum.  Handbook of Physiology. , 1960 .

[25]  P. F. Scholander,et al.  Heat regulation in some arctic and tropical mammals and birds. , 1950, The Biological bulletin.

[26]  G. W. Molnar,et al.  Survival of hypothermia by men immersed in the ocean. , 1946, Journal of the American Medical Association.

[27]  P. Siple,et al.  Measurements of dry atmospheric cooling in subfreezing temperatures , 1945 .

[28]  A. C. Burton,et al.  A STUDY OF THE AVERAGE TEMPERATURE OF THE TISSUES, OF THE EXCHANGES OF HEAT AND VASOMOTOR RESPONSES IN MAN BY MEANS OF A BATH CALORIMETER , 1936 .