What are the major physiological effects of cold?

Cold exposure leads to several physiological effects, including vasoconstriction, which reduces blood flow to the skin to conserve heat. This can result in increased heart rate and blood pressure as the body works to maintain core temperature. Additionally, cold can trigger shivering, a muscle activity that generates heat, and can also impact metabolic processes by increasing energy expenditure. Prolonged exposure may lead to hypothermia and frostbite if the body's thermoregulatory mechanisms are overwhelmed.