why being cold for too long can make you ill

  if you’re in a colder environment, this actually increases the amount of cortisol and the amount of norepinephrine. Physiologically, this is the same as low-level stress and that’s why a cold shower is a great way to wake yourself up!
This is also why being cold for too long can make you ill – as the stress response is suppressing your immune system.
Likewise, if you are hungry, then this triggers a physiological type of stress. Essentially, hunger causes your brain to release cortisol due to a decrease in blood sugar. When blood sugar is low, cortisol is released and the body responds to this as it would any other type of stress.
Why? Because as far as the body is concerned, this is a form of danger. If you are hungry, then you need to become active and get out there in order to seek out a source of food. Ghrelin, the hunger hormone, is released alongside cortisol and myostatin which breaks down tissue to provide energy.
When you eat on the other hand, this causes a sudden spike in your blood sugar. That in turn will cause you to release insulin, which absorbs the sugar for use around the body (either in the muscles and brain, or to be stored as fat).
This also has the effect of leaving behind another substance called ‘tryptophan’, which is found in most foods but doesn’t get absorbed. Tryptophan makes its way through the circulatory system all the way to the brain, where it crosses the blood brain barrier and converts to serotonin (as it is a ‘precursor’ to serotonin). Serotonin is the ‘feel