Fig. 2.
Schematic diagram of the experimental setup for elevating core temperature (Tcore) by hot water leg immersion and for near-infrared (NIR) imaging of the dorsal hand veins. Thermocouple temperature sensors were connected to a data logger for recording Tcore and the skin temperature in dorsal hand (Thand). Another temperature sensor was placed in the water bath to monitor the water temperature (Twater). For data collection, a heart rate (HR) measurement sensor was attached to the subject’s chest, and a monitor was secured around the wrist.