Effect of Gentle Exercise Prior to a Cold Sensitivity Test used to Classify Non-Freezing Cold Injury

摘要

A cold sensitivity test (CST) is one of the assessments used to classify the level of non-freezing cold injury (NFCI) in patients presented to a cold injury clinic. The CST involves sitting in a chamber at 30 C for at least 30 min then immersing the injured site (usually a foot) in water at 15 C for 2 min. The NFCI classification is based on the skin temperature before and 5 min after immersion. Previous studies have indicated that this test may not be very reproducible. In addition, a proportion of uninjured individuals are classified as having a NFCI if this test is used in isolation. The purpose of this study was to examine whether elevating deep body temperature slightly by gentle exercise prior to conducting a CST would increase the reproducibility of the test. Six male subjects with no history of NFCI undertook 10 CSTs with and without prior exercise (stepping, cycling and arm cranking). The results indicated that stepping for approximately 10 min to elevate deep body temperature by 0.3 C reduced the variability in response observed and produced more normal classifications compared to the control condition. An additional finding was that changes in skin temperature were not reflected in changes in blood flow measured using photoplethysmography. The implications of these findings are discussed.