Answer:
Arterioles will likely constrict to prevent the "polar bear" from losing heat from his or her feet.
Step-by-step explanation:
Polar bears and humans are mammals and warm-blooded animals that maintain constant body temperature at the expense of metabolic heat. The skin of polar bear and humans serve in thermoregulation to regulate the body temperature. In response to the lower temperature of surroundings, the blood vessels present in the dermis of skin are constricted. This is done to reduce the blood flow through the skin and thereby reduce the loss of heat from the body.
As the polar bear and humans step in ice and cold water respectively, the arterioles present in their skin would become narrow to slow down the blood flow and thereby, to prevent the heat loss.