A polar bear swim, anyone? Risks and counter-measures.

  • Roy J. Shephard
Keywords: Cardiac arrhythmias, Gasp reflex, Hypothermia, Ventricular fibrillation


Objective. Polar bear swims and other activities involving immersion in frigid water are becoming ever-more popular. This brief article traces the origins of such events, assesses the associated risks to health, and suggests appropriate countermeasures.

Methods. Historical information on polar bear swims, Epiphanal "blessing of the waters" and ultra-long distance swimming events was sought on the internet. Data on associated gasp reflexes, ventricular fibrillation, pulmonary oedema, hypothermia and other hazards, together with appropriate counter-measures was found by standard Ovid/Health Star and Pub-Med searches.

Results. There are few formal statistics on the morbidity and mortality associated with participation in cold water events. Early drowning from poorly coordinated breathing seems a real possibility, and in older individuals cardiac arrhythmias may progress to ventricular fibrillation or asystole as the body cools. However, a dangerous degree of hypothermia is unlikely with immersion of less than 30 minutes. The risks of drowning and cardiac arrhythmias are best countered by undertaking cold water immersion in the presence of someone who is familiar with resuscitative techniques. Hypothermia can be avoided by not remaining in the water longer than 5 minutes; in ultra-ling distance swimming, those with substantial body cooling should be referred to a hospital familiar with the treatment of hypothermia.

Conclusions. The risks of a polar bear swim for a healthy young adult seem minimal, provided that the activity is not performed alone, that immersion is not unduly prolonged, and alcohol ingestion is avoided. However, the immediate shock of immersion may provoke cardiac arrhythmias in vulnerable older individuals. Ultra-long distance swims carry greater risks, and the condition of those involved must be monitored regularly by the crew of pilot vessels.

Author Biography

Roy J. Shephard
Professor Emeritus, Faculty of Kinesiology & Physical Education, University of Toronto
How to Cite
Shephard, R. (2015). A polar bear swim, anyone? Risks and counter-measures. The Health & Fitness Journal of Canada, 8(1), 14-21. https://doi.org/10.14288/hfjc.v8i1.179