Rule of threes (survival)

In survival, the rule of threes is a quick reference guide for how long one can generally stay alive in a survival emergency.^[1]

Normally, it contains the following:

• You can survive three minutes of severe bleeding, without breathable air (unconsciousness generally occurs), or in icy water.
• You can survive three hours in a harsh environment (extreme heat or cold).
• You can survive three days without drinkable water.
• You can survive three weeks without edible food.

These conditions are assuming that the one(s) above it are met. For example, if you have a large quantity of food and water yet are exposed to the environment, then the harsh conditions rule applies. These rules are also useful in determining the order of priority when in a situation.

References