This article was originally published in Issue 1 of our magazine.
Despite all our advancements in medicine, science, and technology, the human body is still a relatively fragile system. Those who have endured a survival situation will be acutely aware of this fact. Whether you're up against a large-scale natural disaster, injured on a solo hike, or stranded by a vehicle breakdown, knowing your physical limits can help you prioritize tasks and stay safe. There's no sense in hunting for food if you're going to die of dehydration, and it's unwise to search for a fresh water source if hypothermia is already setting in.
One easy way to remember the hierarchy of survival risks is known as The Rule of 3s. The simplest version of this rule tells us that 3 hours without shelter, 3 days without water, or 3 weeks without food can be fatal. An expanded version of the rule also includes suffocation in 3 minutes without air. Additionally, 3 days without sleep can lead to delirium, an extreme decline in mental function and motor skills. Of course, differences in physical fitness, age, health, and the surrounding environment can skew these figures, but the general rule is intended as an estimate for the average individual.
The following infographic from Issue 1 of our magazine provides a visual reference for The Rule of 3s, as well as some other important human body tolerances to keep in mind. Click here to download a full-size printable version of this infographic.