Which condition would likely increase susceptibility to hypothermia?

Hypothyroidism is a condition that can significantly increase susceptibility to hypothermia. This is because the thyroid gland produces hormones essential for regulating metabolism and maintaining body temperature. In individuals with hypothyroidism, the reduced production of thyroid hormones leads to a slower metabolism, which can impair the body’s ability to generate heat. Consequently, these individuals may struggle to maintain their core temperature, making them more vulnerable to cold environments and the onset of hypothermia.

The other options would not have the same impact on susceptibility to hypothermia. For instance, peripheral vasoconstriction is a normal physiological response to cold, aiming to conserve heat by reducing blood flow to the skin. Shivering is a protective mechanism meant to generate heat and counteract hypothermia by increasing muscle activity. Piloerection, or the hairs standing up, is also a reflexive action that can create an insulating layer of air but does not significantly increase vulnerability to hypothermia.