As the client enters the cryosauna, the ultra cooled nitrogen gas triggers thermoreceptors in the dermis which send electrical impulses to the brain and central nervous system indicating the extreme external environment. This activates a system wide innate response as the brain prepares to mount a defense mechanism against the cold environment.
Cryotherapy on the Physiological Level
Like any field in modern medicine, we can begin to understand Whole Body Cryotherapy by taking a look at the physiological level. When the body is inside the cryotherapy chamber, the temperature inside this environment can range from -200 degrees F to -274 degrees F. During this session which lasts between 1 to 3 minutes the human body is exposed to extremely cold nitrogen gas and the skin’s surface is rapidly cooled to approximatly 32 degrees F. When the skin’s outer surface reaches freezing for a span as short as 10 seconds, sub-cutaneal temperature receptors located in the dermis are activated sending impulses to the brain that the body is in danger of failing. The brain activates the its innate immune response to the critically cold temperatures by sending signals to the motor neurons in the muscles which in turn contract and constrict in order to send blood to the body’s core and vital organs.
Because the body’s core must always maintain a constant 98.6 degrees F for the organs, tissues and cells to properly function, the slightest change in core temperature can be fatal. This is the reason that, upon receiving signaling from temperature receptors in the skin triggered by the hyper-cooled nitrogen gas within the cryotherapy chamber, the central nervous system must send clear warning to the rest of the body that maintaining the body’s core temperature will be impossible without sending the blood supply from the body’s peripheral to the vital organs at the core. This results in a series of vasoconstriction and vasodilation to quickly get blood to the vital organs, which will show a physcial increase in arterial blood pressure of approximately 10 points.