What Happens When You Freeze To Death? . 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.