“Something old, something new, something borrowed, someone's blue”: a review of the literature and responses associated with cold water immersion

In this chapter the responses associated with immersion in cold water are reviewed. The first experiments into these responses were reported in 1798 and, like a good deal of the work that followed, concentrated on methods of rewarming. The 273 most recently published papers in the area can be broadly categorized into the following groups: adaptation to cold (9% of papers); non-thermal factors influencing thermoregulation (16%); clinically related (22%); diving response or cold pressor test (5%); mathematical modelling of human thermoregulation/prediction of survival time (6%); performance in the cold (13%); and responses evoked by immersion (29%). Of all of these areas, the prediction of survival time remains amongst the most important, but also the area in which it is most difficult to obtain definitive data. This is due to the fact that death may be due to more than one cause (drowning, cardiac problems or hypothermia), and the rate of cooling on immersion can be influenced by a wide variety of factors. These include: sea state and temperature; intrinsic (fat and muscle) and extrinsic insulation (clothing); fitness, gender, and factors that directly influence the capability of the thermoregulatory system, such as hypoglycaemia, hypoxia, drug intoxication and acclimatization.