2007, Piran, Slovenia

Cold physiology
THE EFFECT OF REPEATED COLD WATER IMMERSION ON THE
COLD-INDUCED VASODILATATION RESPONSE OF FINGERS
Uroš Dobnikar 2 , Stelios Kounalakis 1,3 , Bojan Musizza 1 , Stephen S. Cheung 4 &
Igor B. Mekjavic 1
1 Jožef Stefan Institute, Ljubljana & 2 Clinical Centre Maribor, Maribor, Slovenia;
3 National and Kapodistrian University of Athens, Greece
4 Brock University, St. Catharines, Ontario, Canada
Contact person: igor.mekjavic@ijs.si
INTRODUCTION
General and local thermoregulatory mechanisms are activated during cold exposure to
maintain normothermia. Skin cold-induced vasoconstriction is one such local mechanism,
causing a substantial decrease in skin temperatures of the acral parts of the extremities. These
parts of the body have a high surface area-to-mass ratio and are therefore regions of high heat
loss prone to cold injury. A local thermoregulatory response in the extremities, characterized
by cyclic skin vasodilatations (i.e. cold induced vasodilatations or CIVD), causes cyclic
increases in the digital temperatures (Lewis 1930). This presumably protects the digits from
cold injury during severe cold exposure.
In the present study we investigated the effect of 13 repetitive cold water immersions (8°C) of
the whole hand on local cold acclimation of the fingers. Additionally, the effect of cold water
training immersions of the right hand on local acclimation of the contralateral left hand was
investigated.
METHODS
Nine subjects with an average (SD) age of 25 (5) years, height 180.8 (4.8) cm, and weight
80.4 (5.9) kg gave their informed consent to participate. All subjects immersed their right
hand to the wrist in cold (8°C) water for 30 min daily for a total of 13 consecutive days
(excluding weekends). On the first and last day, subjects performed separate immersions of
first their right followed by their left hand. During all experiments, the finger pad skin
temperature of all fingers and the dorsum of the hand were measured every 8 seconds with
thermocouples (Almemo, Ahlborn, Germany). Tympanic temperature (ThermoScan, Braun,
Germany), heart rate (Polar NV, Polar Electro Oy, Finland), blood pressure (Finapres) and
subjective ratings of thermal comfort and temperature sensation were also monitored during
the immersions.
RESULTS
The finger skin temperature responses and the CIVD parameters derived from the local finger
skin temperatures did not significantly change with repeated cold-water immersions. A
decrease in average finger skin temperature was found during training immersions. Subjective
thermal sensations, heart rate and diastolic pressure did not change significantly with training
immersions. The significant transient increase in systolic blood pressure from 130 (6) to 150
(14) mmHg in the first three min of immersion was attenuated after completion of all training
immersions. There was no local acclimation effect on the CIVD response in the fingers as a
consequence of the repeated cold-water immersions. Interestingly, average immersed finger
skin temperatures decreased after cold acclimation suggesting a general insulative acclimation
response.
Also, the finger temperatures and the CIVD parameters of the contralateral untrained hand
decreased at the end of the training immersions. On day 1, the average skin temperatures
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