Previous recreational cold exposure does not alter endothelial function or sensory thermal thresholds in the hands or feet.

In this study, we investigated whether cold-sensitive (CS) individuals, who rewarm more slowly after a mild cold challenge, have impaired endothelial function and sensory thermal thresholds (STTs) and whether this is related to reported cold exposure. Twenty-seven participants with varying previous cold exposure undertook three tests: an STT test, i.e. determination of warm and cold STTs of the fingers and dorsal foot; an endothelial function test, i.e. measurement of cutaneous vascular conductance (CVC) during iontophoresis of ACh on the forearm, finger and foot; and a CS test, involving immersion of a foot for 2 min in water at 15°C followed by 10 min of rewarming in air at 30°C. Toe skin temperature (Tsk ) measured during the CS test was used to form a CS group (<32°C before and 5 min after immersion) and an otherwise closely matched control group [Tsk >32°C; n = 9 (four women) for both groups]. A moderate relationship was found between cold exposure ranking and Tsk rewarming (r = 0.408, P = 0.035, n = 27) but not STT or endothelial function. The Tsk and blood flow were lower in CS compared with control subjects before and after foot immersion [Tsk , mean (SD): 30.3 (0.9) versus 34.8 (0.8) and 27.9 (0.8) versus 34.3 (0.8)°C, P < 0.001; and CVC: 1.08 (0.79) versus 3.82 (1.21) and 0.79 (0.52) versus 3.45 (1.07) flux mmHg-1 , n = 9, P < 0.001, respectively]. However, no physiologically significant differences were observed between groups for endothelial function or STT. A moderate correlation between previous cold exposure and toe Tsk rewarming after foot immersion was observed; however, CS was not associated with impaired endothelial function or reduced thermal detection.