If you have ever really faced "exposure to the elements," you know that a good survival shelter is mandatory. Even so called “moderate temperatures” can seem much colder if you’re exposed for a prolonged time, such as sleeping outside in the wild. Our bodies need to maintain its temperature of 98.6F, but if we’re immersed an environment much lower than that, our internal core can lose heat rapidly. Consider all those people who become hypothermic when they fall into water as warm as 50F. 50F air isn’t much different than water; it just takes longer to go into hypothermia, but it will still occur.
Compounding this heat loss is the fact that when we sleep, our metabolism slows down, so our core temperature naturally drops. Now factor in possibly being wet, and hopefully you see your survival time will be pretty short since illness will soon set in. Along with survival water gear, light-weight food rations, and a means for starting a fire, a good survival shelter is one the four top priorities for your bug out bag gear. The two major components of your bug out survival are a sleeping bag, and a tent.
For your bug out gear, a great sleeping bag is the first priority. Sleeping bags are rated by the minimum temperature they can withstand. Since you really can’t predict what the temperature will be if the SHTF, you’ll want to find a sleeping bag rated for below zero temperatures just in case. Next, since you could be lugging your sleeping bag on your back, you’ll also need to consider a bag that is light weight. Your sleeping is the most important part of your bug out survival shelter, so make sure you go for quality.
Sleeping bags are not usually water-proof (even if they claim to be). To actually keep you dry, you’ll want a good waterproof tent. And just like wearing layered clothing, a tent provides one more layer of insulation between your sleeping bag and the outside. Like sleeping bags, tents are also rated by temperature with the best being called “4-season” tents. Sometimes a manufacturer will call their tents “4-season,” when in fact they are 3-season tents. Although this does happen, just know that a great, extra warm sleeping bag can overcome a slightly overrated tent.
Once you’ve covered your entire basic doomsday prepper bug out gear requirements, you can decide what you’ll like for a more long-term survival shelter. A hardcore, all-out, rugged survival ax could take you far, in terms building a long-term survival structure. An ax, some trees, and a little ingenuity and you could build yourself a cabin wherever you end up. But if you have the budget, and want more security you could also look into a permanent doomsday bunker. Other than extra security, an advantage of owning your own bunker is that you can store years and years of prepper supplies, and survival gear, and would be your home base if you have to start-over. You can either have a bunker built, or you can do it yourself. I would lean towards at least considering building your underground shelter yourself, as the more people who know about your bug out location the more potential, unwanted visitors you may have to fend off.