Surviving a Wet Sleeping Bag
Do all you can to keep your sleeping bag dry and air it out daily. …sure, we’ll get to the info on what to do when a sleeping bag is already soaked, but the smartest thing you can do is to keep your bag dry - or dry it out promptly.
A few simple things can make life more comfortable before a sleeping bag even gets wet. Before the camping trip even starts, setup and check your tent before longer trips to make sure it doesn’t have seam leaks or a torn floor. Hitting the tent with a hose for several minutes or setting it up near a sprinkler is a good idea. Unless you’re planning on camping in hurricane-force winds, make sure the water is falling on to the tent and not spraying at the ground and then splashing inside. Second, carry a sleeping pad on every trip. Putting insulation between you and the ground is the single most important thing to do in even moderate temperatures - especially if your sleeping bag is too wet to use at all. Finally, at every chance you get: drag the bag out of the tent, turn it inside out, and hang it up or lay it out somewhere dry. Even if you’re not sweating in the bag, skin does breathe and the insulation gets damp. Over the course of a week or more if that dampness doesn’t get flushed out the extra moisture can chill you in the bag at night and the bag’s insulation will not loft (”puff up”) enough to insulate well. Even if it’s raining, turn the bag inside out while you’re in the tent. Especially if it’s raining, make sure to keep the bag away from the tent walls and condensation drips. Easy enough? …when you’re cold and stuck inside the tent all day it’s even harder not to stay inside the bag all day long. The extra moisture in the bag if you stay in all day, can make for a cold night once the sun goes down. If you sleep in wet environments often (i.e.: the Pacific Northwest) then consider a synthetic fill bag a down bag with a DriClime or similar waterproof, breathable shell fabric.
(this article is an expanded excerpt from our article: Staying Warmer in the Sleeping Bag you Already Have)
Once you do get your bag wet or damp there are very few things you can do to fix it. The most obvious method is to take a long break during lunch-time or during any breaks between rain showers. Pull your bag out and don’t just lay it out - shake it out and swing it around to get the air moving around it. Be careful to keep it from touching any puddles and stay near the tent if it still looks like rain may hit again. A half-hour break to “auto dry” your bag this way can dramatically help a synthetic bag and will even dry out down enough to make it useful after a good soaking. Without a chance to get a bag reasonably dry during the day, take a few minutes before sleeping to decide your best way to get through the night. A sleeping bag with synthetic insulation can be wrung out (gently, to not tear the insulation) enough to sleep in during moderate temperatures. Down bags are a big problem once the insulation starts to clump, only “auto drying” the bag will make it use as anything more than a blanket.
Once your sleeping bag is wet - it’s time to think about survival. The severity of a wet sleeping bag depends on the temperatures outside. In some warmer temperature ranges sleeping with extra clothes on is just as good as having a dry sleeping bag, in other temperature ranges a wet sleeping bag can be life threatening.
Near-Freezing Temperatues (20°-40° F) are the Most Dangerous:
In near-freezing temperatures the water in even a synthetic bag is dangerous, in a down bag it’s sometimes best to abandon using the bag altogether. Unless it gets below freezing the water in either type of bag will still evaporate and can steal enough body heat to make you hypothermic. Hopefully, at those temperatures you’re carrying a good sleeping bag and decent top and bottom insulation layers. Put them all on before bed and turn in a little early. Do not get inside your sleeping bag. Either open it up and use it like a blanket or don’t use the bag at all. If you have a tent-mate with a dry bag, try to figure out how to share it with them. Assuming that you can find enough warmth to fall asleep the odds are that you’re going to wake up in the early morning when it gets really cold (the coldest hours are from 3am - sunrise). That is why it’s good idea to go to bed early, to get some sleep in before it’s really cold. In the worst case scenario stay awake all night and avoid hypothermia. Make sure to eat something overnight to keep core temperature up. Grab some sleep the next morning once exhaustion sets in, and once it’s warmed up slightly.
Super-Freezing (0° F & lower) Temperatures, Soaking a Bag is Unlikely
Sub-Freezing Temperatures are Nasty, but Survivable
Below freezing (below 20° F) temperatures are a different story than the warmer temperature ranges. Water in the sleeping bag will freeze and frost-up, even when you are inside the bag. Frost in the bag is good and bad. It’s definitely not comfortable or particularly warm, but so long as the insulation can loft before the water inside freezes enough heat can be trapped to get through the night. It’s difficult to completely soak a bag when all the water is frozen, try not to spill the coffee. In the event something like that does happen - wring synthetic out immediately and then lay it out to loft; gently squeeze out down and then lay it out while gently shaking it. These steps will allow the bag’s insulation to puff somewhat before it freezes and the puffiness will trap heat. In cases where a bag isn’t completely soaked this temperature range actually gives some leeway for only a damp bag. In general a sleeping bag can be used as normally, just add a few layers of clothing to yourself to keep moisture away from the skin and even throw a layer of dry clothes over the bag to slow evaporation.