Cold Water Swimming 101

source: Chicago Open Water Swim Group
original: Chicago Open Water Swim Group
author: srherman
date: March 19, 2008

Let’s say you had the misfortune of falling overboard during a boating outing in the middle of Lake Michigan. Assuming that you were wearing your normal clothing, the following chart gives an approximation of your survival time given various temperature scenarios:

Hypothermia Chart
IF THE WATER
TEMPERATURE (F) IS:
EXHAUSTION
OR UNCONSCIOUSNESS
EXPECTED
TIME OF SURVIVAL IS:
32.5 Under 15 Minutes Under 15 - 45 Minutes
32.5 - 40.0 15 - 30 Minutes 30 - 90 Minutes
40.0 - 50.0 30 - 60 Minutes 1 - 3 Hours
50.0 - 60.0 1 -2 Hours 1 - 6 Hours
60.0 - 70.0 2 - 7 Hours 2 - 40 Hours
70.0 - 80.0 3 - 12 Hours 3 Hours - Indefinitely
OVER 80.0 Indefinitely Indefinitely

There are two things to note with regards to this chart:

1. These scenarios do not factor in swimmers who are wearing cold water gear such as wetsuits or neoprene caps.

2. The type of open water swimming we engage in does not involve sub-50F temperatures.

The natural conclusion is that, while swimming for 20-40 minutes in 50F - 60F water may not always be the most comfortable experience, it isn’t really a dangerous one.

This is the first in a series of posts that will focus on cold water swimming. I will be covering a number of areas specific to this topic including gear recommendations, what to expect in the water, and - yes - even hypothermia. Hopefully, by taking some of the mystery out of cold water swimming, we can learn to enjoy this experience safely and without apprehension.

 

---------------------------------------------------------------------------------------

TEMPERATURE (F) IS: TEMPERATURE (C) IS:

33

40

50

60

70

80

0.5

4.5

10

16

21

27