Fig. 1

Representative blood flow and temperature in response to finger cooling for individuals with CIVD response at room temperature (25 °C). This figure is comparable to Fig. 1 in our previous study [9]. White and black dots indicate blood flow and temperature, respectively. The finger was exposed to cold water at 5 °C for 30 min following 10 min of rest (Baseline). The first minimum and maximum temperatures are indicated by black arrows and arrowheads, respectively, suggesting the presence of a CIVD event. The first maximum and minimum blood flows are indicated by white arrowheads and arrows, respectively. The onset time of CIVD (CIVD onset_sbf) is indicated by small arrows. Phase 1 (vasoconstriction; from the onset of cooling to minimum blood flow), phase 2 (prior to CIVD; from minimum blood flow to CIVD onset_sbf), and phase 3 (CIVD; from CIVD onset_sbf to maximum blood flow) are indicated in parentheses as 1–3, respectively. AU, arbitrary units