The 3's of survival are good to know in emergency situations such as being lost or stranded in extreme environments. They're rules of thumb that can help you make informed decisions to help survive.
Imagine you're lost or stranded in an extreme environment such as extreme cold, a desert or Forrest. You'll have to take risks at times. Knowing the survival 3's could save your life.
On average a person can only survive for 3 minutes without air. In any survival situation air is your first priority.
An example of how his is helpful to know. Imagine you have to go underwater to get to another location. Maybe an underwater cave. Decide if you think it would take more that 3 minutes to get there.
You can survive for 3 Hours without shelter in a harsh environment such as extreme heat or cold (unless in icy water).
This is in ideal situations. For example if in extreme heat you'll still want to do all you can to keep cool. In extreme cold you'll need to keep dry and use any other method you have to keep warm.
But if you have to risk leaving a shelter that protects you from the environment. Use the 3 hour rule to help you make informed decisions about how far to travel and when to find/make a new shelter.
Its possible to live for 3 days without water. But in extremely hot conditions with no water, dehydration can set in within an hour.
You can live for 3 weeks without food. Medically speaking, most doctors agree that healthy humans can go up to eight weeks without food as long as they have water.
Of course these are based on ideal conditions and they're not something you can put a stop watch to. Many factors can change the accuracy of these rules. A healthy uninjured person can survive longer.
So use these rules as guide lines. If you're faced with deciding between food and water. You know water is the most immediate need.
Can you cross that desert to get to that oasis in under 3 hours? If not be sure to bring some kind of shelter with you so you can "take a break" and allow you to make it.
So the 3's of survival are good to know and could possibly save your life.
The creator of this guide has not included tools