Humans don't have fur like many of our ancestors, but our bodies still have the ability to adapt to cold weather.
However, when pushed these mechanisms can fail leading to an extreme breakdown.
So, what actually happens to your body and brain when you freeze to death?
Hypothermia occurs when the core body temperature drops below 37 degrees Celsius, so in the event that the body is exposed to extreme cold, within minutes signals are sent from the skin to the hypothalamus producing what is known as the Thermoeffector.
Response.
First, the blood vessels in our skin narrow, allowing the body to maintain its core temperature by reducing the blood flow on its surface, known as Vasoconstriction.
Additionally, brown adipose tissue, located throughout the body, also activates using high levels of glucose and lipids to produce heat via a process called Nonshivering.
Thermogenesis.
But, if all else fails our body undergoes Shivering Thermogenesis as a last-ditch effort By constantly contracting our skeletal muscles, our body induces shivering in an attempt to produce enough heat to prevent hypothermia.
However, if you remain exposed to the cold, within 30 minutes you could get frostbite, which is when your skin and other tissues literally begin to freeze.
