Lifestyle
As a response to cold, your body generates heat by involuntarily contracting and relaxing muscles, also known as shivering.
Exposure to cold can increase insulin sensitivity, allowing your body to use glucose more efficiently and produce more energy to maintain body temperature.
Brown adipose tissue, or brown fat, is a type of fat that generates heat by burning calories.
In addition to shivering, your body can produce heat through non-shivering thermogenesis. This is when your metabolic rate increases.
When exposed to cold, your body reduces blood flow to your skin and extremities to conserve heat for vital organs which constriction of blood vessels maintaining core temperature.
Humans can also make behavioral changes and these adaptations include wearing warm clothing, seeking shelter, and consuming more calories to provide energy for heat production.