Journal of Applied Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

J Appl Physiol 84: 185-189, 1998;
8750-7587/98 $5.00
This Article
Right arrow Full Text Free
Right arrow Full Text (PDF) Free
Right arrow Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by O'Brien, C.
Right arrow Articles by Sawka, M. N.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by O'Brien, C.
Right arrow Articles by Sawka, M. N.

Vol. 84, Issue 1, 185-189, January 1998

Hypohydration and thermoregulation in cold air

Catherine O'Brien, Andrew J. Young, and Michael N. Sawka

United States Army Research Institute of Environmental Medicine, Natick, Massachusetts 01760

O'Brien, Catherine, Andrew J. Young, and Michael N. Sawka. Hypohydration and thermoregulation in cold air. J. Appl. Physiol. 84(1): 185-189, 1998.---This study examined the effects of hypohydration on thermoregulation during cold exposure. In addition, the independent influences of hypohydration-associated hypertonicity and hypovolemia were investigated. Nine male volunteers were monitored for 30 min at 25°C, then for 120 min at 7°C, under three counterbalanced conditions: euhydration (Eu), hypertonic hypohydration (HH), and isotonic hypohydration (IH). Hypohydration was achieved 12 h before cold exposure by inducing sweating (HH) or by ingestion of furosemide (IH). Body weight decrease (4.1 ± 0.2%) caused by hypohydration was similar for HH and IH, but differences (P < 0.05) were found between HH and IH in plasma osmolality (292 ± 1 vs. 284 ± 1 mosmol/kgH2O) and plasma volume reduction (-8 ± 2 vs. -18 ± 3%). Heat debt (349 ± 14 among) did not differ (P > 0.05) among trials. Mean skin temperature decreased throughout cold exposure during Eu but plateaued after 90 min during HH and IH. Forearm-finger temperature gradient tended (P = 0.06) to be greater during Eu (10.0 ± 0.7°C) than during HH or IH (8.9 ± 0.7°C). This suggests weaker vasoconstrictor tone during hypohydration than during Eu. Final mean skin temperature was higher for HH than for Eu or IH (23.5 ± 0.3, 22.6 ± 0.4, and 22.9 ± 0.3°C, respectively), and insulation was lower on HH than on IH (0.13 ± 0.01 vs. 0.15 ± 0.01°C · W-1 · m-2, respectively), but not with Eu (0.14 ± 0.01°C · W-1 · m-2). This provides some evidence that hypertonicity impairs the vasoconstrictor response to cold. Although mild hypohydration did not affect body heat balance during 2-h whole body exposure to moderate cold, hypohydration-associated hypertonicity may have subtle effects on vasoconstriction that could become important during a more severe cold exposure.

hypovolemia; hypertonicity; furosemide; cold-induced vasodilation

The Journal of Applied Physiology 84(1):185-189


This article has been cited by other articles:


Home page
 J. Appl. Physiol.Home page
S. N. Cheuvront, R. Carter III, J. W. Castellani, and M. N. Sawka
Hypohydration impairs endurance exercise performance in temperate but not cold air
J Appl Physiol, November 1, 2005; 99(5): 1972 - 1976.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
C. O'Brien, B. J. Freund, A. J. Young, and M. N. Sawka
Glycerol hyperhydration: physiological responses during cold-air exposure
J Appl Physiol, August 1, 2005; 99(2): 515 - 521.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
C. O'Brien and S. J. Montain
Hypohydration effect on finger skin temperature and blood flow during cold-water finger immersion
J Appl Physiol, February 1, 2003; 94(2): 598 - 603.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
P. N. Ainslie, I. T. Campbell, K. N. Frayn, S. M. Humphreys, D. P. M. MacLaren, T. Reilly, and K. R. Westerterp
Energy balance, metabolism, hydration, and performance during strenuous hill walking: the effect of age
J Appl Physiol, August 1, 2002; 93(2): 714 - 723.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
J. W. Castellani, A. J. Young, C. O'Brien, D. A. Stulz, M. N. Sawka, and K. B. Pandolf
Cold strain index applied to exercising men in cold-wet conditions
Am J Physiol Regulatory Integrative Comp Physiol, December 1, 2001; 281(6): R1764 - R1768.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
C. O'Brien, A. J. Young, D. T. Lee, A. Shitzer, M. N. Sawka, and K. B. Pandolf
Role of core temperature as a stimulus for cold acclimation during repeated immersion in 20{degrees}C water
J Appl Physiol, July 1, 2000; 89(1): 242 - 250.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Regul. Integr. Comp. Physiol.Home page
D. S. Moran, J. W. Castellani, C. O'Brien, A. J. Young, and K. B. Pandolf
Evaluating physiological strain during cold exposure using a new cold strain index
Am J Physiol Regulatory Integrative Comp Physiol, August 1, 1999; 277(2): R556 - R564.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online