Sleep Systems
I have chosen to use the term "sleep systems" because (in many ways) the subject of people's sleeping gear is much more complex than just a "sleeping bag". For starters, not everyone uses a sleeping bag. Some people use quilts. Also, there is the entire matter of having some form of insulation UNDERNEATH you--usually in the form of a sleep pad. Thus, I will use the phrase "sleep system" in this article.
SLEEPING BAG vs. QUILT (or something Hybrid)
For my first 38 years of camping and backpacking, I pretty much used only sleeping bags. For the past 14-15 years, I have used almost only quilts. Both quilts and sleeping bags will accomplish the same general task. And, both sleeping bags and quilts have advantages and disadvantages.
Sleeping bags (and quilts) get their insulation capability from having "loft"---i.e. the "fluffiness" of the down or synthetic fibers traps and retains the warm air of your body heat. The more "loft" that you have-- (usually) the greater the insulating value and the warmer you will feel.
The biggest DISADVANTAGE of a traditional sleeping bag-- (especially in regard to backpacking) is the fact that most of the down or synthetic insulating fibers (located on the bottom or underside of the sleeping bag) provide very little insulation value--because your body weight crushes and compresses much of the "loft". Yet, all of that (mostly unused) insulation material on the underside or bottom of the sleeping bag still adds weight to the sleeping bag--and you have to carry that (mostly unused) weight around with you in your backpack. The (unused) insulation material on the underside of the sleeping bag also adds bulk/volume that takes up more room in your pack.
Conversely, (unlike a sleeping bag) a quilt has NO "underside" or "bottom". Thus, a quilt has no "unneeded" insulating material on the underside that you have to carry around all day in your backpack.
A HYPOTHETICAL EXAMPLE TO CONSIDER: Let's assume that a certain sleeping bag has 2 lbs. of insulating material (either goose down or synthetic fibers). When you are inside of the sleeping bag, roughly half of that insulating material will be located above you when you sleep and nearly half will be underneath you (being crushed and compacted by your body weight and losing much of its insulation value). Now, imagine having a quilt with 2 lbs. of insulating down or fibers. Almost the entire 2 lbs. of insulating material will be located above you when you are sleeping--helping to trap your body heat and helping to keep you warm.
That is why I chose to switch to a quilt. I liked the fact that most of the insulating material of a quilt is located above me-- keeping me warm and it is not below me --being crushed and going mostly unused. Thus, (for the same weight as the sleeping bag) I can have a thicker, "loftier" and "warmer" quilt. In many ways, using a quilt is pretty much like just bringing the top of your sleeping bag--and leaving the portion that is underneath you--at home. A quilt can be a third or even half lighter than a sleeping bag--but still provide essentially the same insulating value and "warmth". That weight savings can be a big advantage when you are backpacking and carrying everything in your pack.
THAT BEING SAID, quilts also have a couple of SIGNIFICANT DISADVANTAGES. 1) Quilts can be drafty and chilly. Every time that you move or roll in your sleep, the quilt can slide off of you and/or cool air can blow in from around all the sides and edges of the quilt. One way to limit this problem is to get a much bigger quilt. However, getting a much larger quilt sort of defeats any weight savings that you hope to achieve by carrying a quilt instead of a sleeping bag. 2) Because the quilt has no underside, that means that you have to sleep directly on your sleep pad, or on the dirty/muddy ground, or on your tent floor or ground cloth. That can sometimes be a bit messy, sticky, sweaty, dirty and/or gross--unless you use some sort of cloth sheet (or cloth sleeping bag liner) between your body and your sleep pad (or between your body and your tent floor or ground cloth). However, carrying a sheet or a sleeping bag liner adds more weight to carry (and diminishes the biggest benefit of using a quilt--namely, reducing the total weight of your sleep system).
Even though I typically choose to use a quilt for the significant weight savings, I sometimes really do miss being inside of a nice, warm, sleeping bag--that provides protection and warmth on all sides--and keeps out drafts. (Although my body weight crushes the "loft" of the down or synthetic insulating material-- even when crushed, that insulating material still DOES provide SOME warmth and softness beneath me. The question is, do I want to carry an extra 1-3 pounds all day while hiking--just to be able to have cloth and insulation around me on all sides when I sleep? Most of the time, I am not willing to carry the extra weight. Thus, I use my quilt).
THERE ARE NOW SOME "HYBRID" FORMS OF SLEEPING GEAR. You can buy some special sleeping bags that have just a fabric underside--but the underside has no insulation/filling. It is just the fabric. This significantly lowers the weight of the sleeping bag. And, because this cloth underside is sewn/attached to the upper part of the sleeping bag, this helps prevent the top from slipping off of you overnight and cuts down on cold air blowing in from around the edges.
There are some quilts that come with attached straps (or attachable /detachable straps). You can place the straps under your body (or under you and your sleeping pad) and the straps will help to hold the quilt in place and keep it from sliding off of you while you sleep. Some quilts also come with a "foot box" permanently built into the design of the quilt (or they come with things like velcro, straps, or cords that allow you to easily create a "foot box" in your quilt. What's a foot box ? It is similar to the fully enclosed area of a sleeping bag where you place your feet, A foot box design helps keep your feet warmer when you are using a quilt and helps to keep the quilt from sliding off of you as easily. Here is a photo of a quilt (from Enlightened Equipment) with a foot box permanently sewn into the quilt's design. Remember, you would not be sleeping on top of this quilt. You would flip this quilt over--and have the quilt covering your your body and your feet would be inside of the foot box.
Sleep Pads
This next statement often comes as a surprise to many people. The primary purpose of a sleep pad is not to provide additional comfort and softness (like a mattress). The primary purpose of a sleep pad is to provide additional insulation and "warmth" beneath you. The softness and comfort provided by a sleep pad are just a nice added bonus.
Thus, many people select a sleep pad using all of the wrong criteria (if they even put very much thought at all into their sleep pad purchases). Please don't select a sleep pad based solely upon how soft or comfortable it is to sleep upon. It is equally (or even more) important to give significant consideration to how that sleep pad will contribute to keeping you warm when you sleep.
One of the primary reasons that a person gets cold when they sleep outdoors is THE COLDNESS OF THE SLEEPING SURFACE AND HEAT LOSS FROM BENEATH THEIR BODY. Even though it might not feel "cool to the touch"---the ground (and/or the floor of a wooden shelter) probably rarely get much above a temperature of 60 degrees Fahrenheit (on Isle Royale) and much of the time those surfaces are much cooler than that. Your typical body temperature is approximately 98.6 degrees. So, even at their warmest, the ground (and shelter floors) of Isle Royale are still much colder than your body temperature and they are going to cool your body down when you sleep on them for many hours.
Allow me to give an overly simplified mental image for use in our discussion. Imagine that you are sleeping on top of a huge block of "ice" that can magically get up to about 60 degrees without melting. Would you REALLY just want to set your tent and your sleeping bag on top of that huge block of ice--- WITHOUT having some additional type of insulation underneath you? That is where the sleep pad comes in. The sleep pad is the "insulation" between you and the huge block of ice. With that "ice block" image firmly in your mind, are you going to pick your sleep pad--based solely upon how soft and comfortable the sleep pad is--or are you going to give a significant amount of consideration to how much insulation value that the sleep pad is going to provide between you and that huge block of ice?
That insulating value is measured in terms of something called an "R-Value". The higher the "R-Value"--the greater the insulating capabilities of the sleep pad. You don't JUST want a sleep pad that is soft and comfy. You also want a sleep pad that has a good R-Value. The reason that some people are "cold" when they sleep, is NOT because they have a sleeping bag (or quilt) that is "too cold". Oftentimes, people are "cold" because they use NO sleep pad--or because they have a sleep pad with a pretty low "R-Value". The chances are, if they get a sleep pad with a higher R-Value, that very same sleeping bag will now keep them feeling much warmer.
CLICK HERE FOR A GOOD ARTICLE FROM REI CO-OP REGARDING SLEEP PADS
Thus, many people select a sleep pad using all of the wrong criteria (if they even put very much thought at all into their sleep pad purchases). Please don't select a sleep pad based solely upon how soft or comfortable it is to sleep upon. It is equally (or even more) important to give significant consideration to how that sleep pad will contribute to keeping you warm when you sleep.
One of the primary reasons that a person gets cold when they sleep outdoors is THE COLDNESS OF THE SLEEPING SURFACE AND HEAT LOSS FROM BENEATH THEIR BODY. Even though it might not feel "cool to the touch"---the ground (and/or the floor of a wooden shelter) probably rarely get much above a temperature of 60 degrees Fahrenheit (on Isle Royale) and much of the time those surfaces are much cooler than that. Your typical body temperature is approximately 98.6 degrees. So, even at their warmest, the ground (and shelter floors) of Isle Royale are still much colder than your body temperature and they are going to cool your body down when you sleep on them for many hours.
Allow me to give an overly simplified mental image for use in our discussion. Imagine that you are sleeping on top of a huge block of "ice" that can magically get up to about 60 degrees without melting. Would you REALLY just want to set your tent and your sleeping bag on top of that huge block of ice--- WITHOUT having some additional type of insulation underneath you? That is where the sleep pad comes in. The sleep pad is the "insulation" between you and the huge block of ice. With that "ice block" image firmly in your mind, are you going to pick your sleep pad--based solely upon how soft and comfortable the sleep pad is--or are you going to give a significant amount of consideration to how much insulation value that the sleep pad is going to provide between you and that huge block of ice?
That insulating value is measured in terms of something called an "R-Value". The higher the "R-Value"--the greater the insulating capabilities of the sleep pad. You don't JUST want a sleep pad that is soft and comfy. You also want a sleep pad that has a good R-Value. The reason that some people are "cold" when they sleep, is NOT because they have a sleeping bag (or quilt) that is "too cold". Oftentimes, people are "cold" because they use NO sleep pad--or because they have a sleep pad with a pretty low "R-Value". The chances are, if they get a sleep pad with a higher R-Value, that very same sleeping bag will now keep them feeling much warmer.
CLICK HERE FOR A GOOD ARTICLE FROM REI CO-OP REGARDING SLEEP PADS
Always Remember It is a Sleep "SYSTEM"!
Staying warm and comfortable when you sleep outdoors IS NOT based just upon how "warm" your sleeping bag (or quilt) is. You also need to take into consideration the R-Value (and comfort) of the sleep pad. You need to consider how the tent floor (and ground cloth/"footprint") keep you dry (and keep you further insulated) from the dampness and coolness underneath you. You also have to consider in what ways your tent, wooden shelter, hammock and/or bivy sack protect you from wind, cool air, and dampness on all sides.
Furthermore, your clothing choices when you sleep are a part of your total "Sleep System". Dry and clean sleeping clothes are warmer and more comfortable than clothes that are even just slightly damp and dirty from perspiration. A "wool" hat or "beanie" will help keep your head and ears warm. Socks (or down booties) can help keep your feet warm. Wearing a fleece or down jacket when you sleep can add to the insulating value and "warmth" of your sleep SYSTEM.
It is important to consider ALL ELEMENTS of your entire "SLEEP SYSTEM".
A WORD ABOUT SLEEPING BAG LINERS
The biggest benefit of sleeping bag liners--is that they help to keep your sleeping bag (or quilt) cleaner--and they may provide the equivalent of A FEW extra degrees of "warmth" or insulation. DO NOT--I repeat-- DO NOT believe (or trust) the manufacturer's claims that the liner will add 10, 15--or even 20 degrees of added warmth to your sleeping bag or quilt--because the liner WILL NOT do that--and you will become cold if you trust those estimates.
Furthermore, your clothing choices when you sleep are a part of your total "Sleep System". Dry and clean sleeping clothes are warmer and more comfortable than clothes that are even just slightly damp and dirty from perspiration. A "wool" hat or "beanie" will help keep your head and ears warm. Socks (or down booties) can help keep your feet warm. Wearing a fleece or down jacket when you sleep can add to the insulating value and "warmth" of your sleep SYSTEM.
It is important to consider ALL ELEMENTS of your entire "SLEEP SYSTEM".
A WORD ABOUT SLEEPING BAG LINERS
The biggest benefit of sleeping bag liners--is that they help to keep your sleeping bag (or quilt) cleaner--and they may provide the equivalent of A FEW extra degrees of "warmth" or insulation. DO NOT--I repeat-- DO NOT believe (or trust) the manufacturer's claims that the liner will add 10, 15--or even 20 degrees of added warmth to your sleeping bag or quilt--because the liner WILL NOT do that--and you will become cold if you trust those estimates.
LINKS TO INFORMATION REGARDING TEMPERATURE RATINGS OF SLEEPING BAGS AND QUILTS
Click on these links to read more about the temperature ratings of sleeping bags and quilts. (My opinion: Sleeping bags and quilts tend to only be suitable for temperatures which are roughly ten degrees warmer than the sleeping bag or quilt is rated. EXAMPLE: A "30 Degree" sleeping bag is probably only suitable in temperatures which are 40 degrees--or warmer).
LINKS TO INFORMATION REGARDING SELECTING A SLEEPING BAG
Click on the links to go to the articles.
LINKS TO INFORMATION REGARDING SELECTING A BACKPACKING QUILT
Click on the links to go to the articles