Why do we not put our sleeping pads in our sleeping bags? Does it change the R rating? I know Big Agnes has an integrated one with one of their bags but I suspect I'm missing something here.

Thanks,

Tavalon

I don't know. Try it at home and see what happens. It's probably because pads were designed after sleeping bags and evolved from piling insulating materials on the ground.

Because....If you are in a mummy bag, and you turn to the side, the whole bag turns with you, most likely. If you put the pad inside the bag, your pad will be on your back, not insulating, when you roll to the side. If you are only a back sleeper, you'd be ok with the pad inside.
I also use the pad to protect the bag if on the ground and not in a hammock.

IMHO, Dryer has the right answer. I turn from side to side frequently and learned as a child to take the sleeping bag with me when I turn. My pad would most certainly end up on top!

The separate arrangement also keeps the sleeping bag off the tent floor (keeping it cleaner and, in humid conditions, dryer) (no pun intended!) and allows us to use different sleeping bag/pad combinations in changing temperature conditions.

The only stupid question is the one you don't ask! I have found in my other hobby (Civil War reenacting), that a lot of seemingly silly questions (the most frequent is "Aren't you hot in all that stuff?") are not stupid at all, but are the result of not quite knowing how to ask, for example, how our ancestors coped with the heat. Treating all questions as legitimate very often leads to useful discussions about our history, which is our primary purpose in this hobby.

Ok, Mouse, I'll ask....how did our ancestors cope with the heat? I've been invited to participate with a CSA canon crew and all that wool in Texas heat looks, well, hot.

Natural fabrics make a lot of difference. So does relatively loose clothing and spending the hot hours in the shade doing sedentary activities. I'm actually cooler in several relatively loose layers of cotton than I am in a single snug-fitting layer of knit synthetics! Big secret--when it's really hot, ladies retire to their rooms to remove their corsets during the heat of the day. Another big secret--full skirts (lots of ventilation below the waist) are more comfortable than tight-fitting slacks or shorts. Those hoop skirts became popular because they are lighter and more ventilated than several layers of petticoats. Note how houses were built in the days before air conditioning--well-shaded windows, and the second (or third) story providing protection for the lower story/stories. Lots and lots of shade trees make considerable difference.

This of course doesn't apply to the military in their wool uniforms! However, wool is actually more breathable to sweat than synthetics. It does appear that the Confederate troops dressed more sensibly--they wore broad-brimmed hats (far better than the Union's useless kepis) and they often fought in shirtsleeves. Confederate uniform standards were a lot less strict than the Union's, probably because the uniforms themselves became scarcer and scarcer as the war went on. Have fun with the cannon! Keep hydrated!

I attended a re-enactment last month as a spectator (21st century dress) for the first time. I swear I was a lot hotter than I was at the July 4 weekend re-enactment in my full 19th century getup, in very similar temperature conditions. Of course I wasn't chasing a 9-year-old grandson around at the July 4 event!

Now, let's get back to the OP's excellent question! If you're a stable back sleeper, the Big Agnes concept of including the pad in the sleeping bag makes a lot of sense. In other words, there's a lot of YMMV (Your Mileage May Vary) involved here. Sleep styles are extremely individual.

In a word, Girth. A mummy bag is designed to fit fairly closely around you, to minimize air space (and the amount of dead air you have to heat.) There simply isn't enough room inside a properly-sized mummy bag to put both you and the pad in there - that's the logic, anyhow. If you put the pad inside, it will feel very tight and may, in some cases, compress the down somewhat - which inhibits the bag's ability to loft, which is what helps you stay warm.

In fact, if you can fit the pad inside the bag without having it be uncomfortably tight, it might be worth doing, simply to fill some of that space.

True! I was thinking of the BA bags that have a pocket for the pad instead of insulation on the bottom. The same problem would still apply to us tossers and turners, though, plus flexibility is lost when changing to different seasons.

That's how I read your post (mine was to the original post.) The separate compartment absolutely precludes side-to-side (at least, if you don't want you face in the side of the hood.) Like many others, I learned to roll the bag with me early on.

Thank you, both you and the last person for explaining that. I always moved in the bag and kept it in the same position - one of the reason's I hated mummy bags!

But that really makes sense. Thank you to everyone, especially you and the poster above, for not making me feel foolish and yet, making me more educated.

Tav.

Depending on the conditions you're camping in, there's another option that sort-of-ly brings the pad into the bag: quilts. These are essentially hoodless bags, usually with a foot pocket, that you simply drape over you while you lay on the pad. This works down to about 30-40 degrees; below that, you need insulation around your head, in the form of a hood (most heat-efficient.)

For many years, I'd use a 40 degree hoodless Western Mountaineering MityLite that way, leaving it zipped at the foot to put my feet in, then just draping the rest over me.

This summer, I made the switch to an actual quilt, which is a bit lighter and less bulky. I'm using a 35 degree (allegedly) Thermarest Alpine Down Blanket with a NeoAir All-Season full length pad. It's a very comfortable system, so far; as temperatures drop into the 40s, I'll also carry a fleece top and pants, long johns, and a down jacket with a hood. If I need to (for example, the lows are lower than forecasted), I can wear those clothes to bed and use the hood instead of a bag with a hood. (The hood on a jacket will roll with you.)

Let's talk about pads: a warm bag or quilt can be completely undone by the wrong pad. If you're sleeping on snow on an air-filled pad (one without any insulation inside the pad), you'll sleep cold even with a great bag. (Don't ask how I know this. Suffice it to say "I have a friend" who learned this in January.) Pads aren't rated by temperature, like bags; they're rated by r-value. If I recall right, my NeoAir is an r-value of 5. Also, in cold weather, I prefer a full-length (66 or 72 inch long) pad; in warm weather you can use a shorter pad (40-48 inches long) and put your pack under your lower legs.