The temperature of cold water is considered to be a maximum of 70 degrees Fahrenheit. A person can survive in water temperatures of 70 to 80 degrees Fahrenheit for 3 to 12 hours before hypothermia sets in, according to Minnesota Sea Grant.
The range of cold water temperatures is considered to be from 32.5 degrees Fahrenheit to roughly 70 degrees. As water temperature falls, a person's ability to survive before hypothermia and unconsciousness set in decreases. In 32.5-degree water, a person will only be able to remain conscious for roughly 15 minutes. If the temperature is between 50 and 60 degrees, the person can remain conscious for 1 to 2 hours. In water temperatures above 80 degrees, a person can survive indefinitely.