Blood pressure and thermal responses to whole body cold exposure in mildly hypertensive subjects

Six mildly hypertensive subjects were exposed three times to - 15 degreesC (wind 3.5 m/s) for 15 min. After an initial exposure for familiarisation, second and third exposures were arranged in a random double blind, crossover fashion after a week's ingestion of hydrochlorothiazide or placebo. Cold decreased skin temperatures, but not rectal temperature. Blood pressure increased 30/20 mmHg and heart rate decreased 12 beats/min by cold. Blood pressure seems to react in 3 min to changes in ambient temperature. The skin temperatures of uncovered body parts were apparently responsible for that. Hydrochlorothiazide did not affect either cardiovascular or thermal responses in cold. (C) 2004 Elsevier Ltd. All rights reserved.