Insulated blow up sleep pad used inside sleeping bag?

[petedelisio]

As long as it fits and doesn't cram insulation or the wearer, what are known and or assumed expected results?

Roomy Down bag in particular...
Thoughts?

[Brewguy]

If it fits it would work just fine. I think most properly sized mummy bags won't have that sort of room unless you're a small child.

[petedelisio]

Some controls to eliminate some expected extreme variables.
The pad is exactly the footprint of a one position sleeper..

I suppose the foremost question would be of the bag insulation being largely crushed under the pad apposed to crushed on top of the pad.
It's a pad with "divets" for some small areas of loft.

I understand many of the other heat loss areas. Almost so, that the pad should be smaller than the sleepers "non moving" foot print.

[petedelisio]

"Non moving" sleepers* footprint.

[psyculman]

It's ok if you sleep on your back the whole night, but you can't roll over on your side with the pad in the bag. Just sayin.

[jeffmeh]

That's what a quilt is for.

[CalebJ]

I've done it quite a bit whenever the pad fits well in the bag. It's (for me) the most comfortable way to sleep while backpacking.

[petedelisio]

Thanks for all the input so far. All very helpful.

[Deadeye]

expected result... a dirtier sleeping bag

[HankIV]

That's what a quilt is for.

That’s what I was thinking. Why carry the portion of the sleeping bag that you’re not going to use?

[peakbagger]

I end up using my sleeping bag as a quilt most of the time as I have wide shoulders and even a extra girth bag like a Western Mountaineering Megalite is tight. The trade off is in cold weather sleeping on a regular air mattress can be cold. I think Big Agnes has an inflatable with some sort of internal insulation that helps with that but it weighs more.