what is the long term adaptation that will allow your body to generate heat

Hello Pinky,

When the environment is very cold, life can depend on the ability of our bodies to reduce heat loss and to increase internal heat production.  As Bergmann and Allen observed, the human physiological response to cold commonly includes the evolution of more massive, compact bodies with relatively less surface area.  However, short term acclimatization to the cold also occurs.  A normal initial physiological response is the narrowing of blood vessels near skin surface (vasoconstriction).  This preserves core body heat by reducing peripheral blood flow.  As a consequence, the skin cools and less heat is lost from the body by radiation.  However, if the environmental temperature is below the freezing point, prolonged vasoconstriction can result in dangerous frostbite.  As a consequence, the body's internal temperature regulating mechanism responds by dilating the peripheral blood vessels (vasodilation), thereby increasing the flow of warm blood near the skin surface.  The body normally alternates back and forth between vasoconstriction and vasodilation to compensate for the risks of both conditions.  This cycling is known as the Lewis hunting phenomenon).  Shivering can also cause a short-term warming effect. The increased muscle activity in shivering results in some heat production.

There are three additional important types of biological responses to cold conditions found among some human populations around the world:

1.     increased basal metabolic rate
2.     fat insulation of vital organs
3.     long term change in blood flow patterns

People living in harsh subarctic regions, such as the Inuit, traditionally consumed large quantities of high calorie fatty foods.  This significantly increases the basal metabolic rate, which, in turn, results in the production of extra body heat.  These peoples also wore heavy clothing, often slept in a huddle with their bodies next to each other, and remained active when outdoors.