Everyone experiences a shortening of breath when they get into uncomfortably cold water ... Everyone also experiences a 30-80% decrease in cognitive function, in particular of the prefrontal cortex; the metabolism of your frontal cortex goes down; the metabolism, meaning the activity of brain areas associated with stress and panic, goes way up. And so, anchoring your mind in cognitive activities as you get into the cold can be very, very helpful for maintaining clarity of mind.