Every year in the US about 150 people die while out and about in national parks, more than 1,000 die in hunting-related incidents and thousands of backcountry enthusiasts get in deep trouble and require a Search and Rescue team to save them; with dozens of those folks dying while awaiting rescue. Most fatalities are the result of poor preparation. Bad weather descends and people get lost. They wander without water or shelter, often injuring themselves in the process. If they survive they often suffer frostbite, hypothermia, dehydration, trench foot or some combination of them all.
Here are just a few choice gems from The Prepper Journal's 11 Ways A Condom Can Save Your Life: starting fires (they're great at protecting tinder from moisture), hunting for food (sexiest slingshot ever!), and transporting up to two liters of water (yes, rule 34 applies; no, we won't provide the link). They also make serviceable stand-ins for rubber gloves and can be used to protect the muzzle of your other essential survival tool (killing it right now).
Firearms instructor and survivalist Colonel Jeff Cooper wrote on hardening retreats against small arms fire. In an article titled "Notes on Tactical Residential Architecture" in Issue #30 of P.S. Letter (April 1982), Cooper suggested using the "Vauban Principle", whereby projecting bastion corners would prevent miscreants from being able to approach a retreat's exterior walls in any blind spots. Corners with this simplified implementation of a Vauban Star are now called "Cooper Corners" by James Wesley Rawles, in honor of Jeff Cooper. Depending on the size of the group needing shelter, design elements of traditional European castle architecture, as well as Chinese Fujian Tulou and Mexican walled courtyard houses, have been suggested for survival retreats.
For global catastrophic risks the costs of food storage become impractical for most of the population  and for some such catastrophes conventional agriculture would not function due to the loss of a large fraction of sunlight (e.g. during nuclear winter or a supervolcano). In such situations, alternative food is necessary, which is converting natural gas and wood fiber to human edible food.
In this review guide we’re going to shine a light on 21 essential pieces of survival gear everyone should seriously consider having in their survival pack. We’re going to concentrate on survival gear aimed at aiding those engaged in outdoor activities and not those forced from their home by natural disaster, although some of these products will also be useful in those types of situations. We’ll start by highlighting 3 pieces of must-have survival gear; those things we would not venture into the wilderness without, and then move on to other valuable survival aids you’ll want to think about packing.