Physics of layering bedsheets?

OK, it probably has nothing to do with physics, but this has been bothering me since I was 12 or so.

When putting sheets/blankets on your bed in the winter, everyone knows that the best arrangement is to have the sheet, then the blanket then the comforter. I have no idea why this works, but it does.

I recall the the first time I heard that was when I was at my grandfather’s house. I complained about being cold and when he examined my bed, he saw that I had put the blanket down and then the sheet. He explained that he used to do things that way too, until the Army taught him differently.

My reasoning at the time was that the blanket would trap, via all the stuffing, the heat while the sheet on top being denser (or so it appeared to my mind and if that’s the right word) would keep said heat from dissipating.

I based my reasoning on the idea that the outer layer of my jacket is the thickest part and the liners aren’t made to be weatherproof.

I am still at a loss to explain how the sheet-blanket-et. al. system works. Anyone?

What’s the difference between a blanket and a comfortor?

My dad’s house used to have these horrible wool blankets that were itchy as hell. We put sheets under them just to avoid having our skin sanded off.

A conforter is a very thick, puffy, soft blanket that has down or maybe a lofty synthetic substance a a filler. Think a giant sleeping bag with a cotton cover that covers the entire bed. I am sure that you know what a blanket is. They are not the same.

Were you in fact warmer after switching to sheet/blanket/comforter or was your perception changed by the fact that the sheet felt different than the blanket?

If you were in fact warmer then my WAG is that having the sheet next to you works better because the sheet traps warm air closest to your skin. The blanket layers provide a buffer from the much colder air in the room.

Remember, what insulates is trapped, non-moving air. Putting a heavy blanket on top of a comforter will smoosh all the air out of the fluffy stuff, so there’s less insulation. This seems pretty clear to me.

The main reason for having a sheet bottommost is to keep the blankets clean. The sheet then gets all your body oils and dirt, but that’s OK because you wash the sheet every week or whatever.

Whether moving the sheet above the blanket would make a difference, I’m not sure.

I don’t think it’s about warmth at all.

The sheet is there because you want to have something soft and easy to wash next to your body. You don’t want your blankets getting all gross with sweat and whatever. The blanket comes next because it’s warm. But it’s probably pretty ugly, so it gets covered with a decorative and easy to spread out comforter.

i taught the same arrangement too, but i was taught to sleep on top of the sheet. in other words, between the sheet and blanket, i am always warmer that way

Here’s the the old way:


Here’s the new way:

Comforter (if really cold)

The new way is definitely much warmer than the old and adding that extra sheet on top of me is significantly warmer than not having a topsheet.

Quercus so, the space between the fibers or whatever where the air is being kept is the most important part? How does the extra sheet aid in this? Merely by creating two extra spaces for insulation (between me and sheet and between sheet and blanket?

does bedsheet=fitted sheet?

Sheets conform most closely to the body, blankets next, and stiff comforters the least. Comforters provide the most insulation, then blankets, then sheets.
Your body produces about 100 watts of heat, which travels away from you mostly by convection. Any of the coverings will limit convection, but sheets will limit the air tucked in with you to the smallest volume. Being poor insulators, they need a blanket on top to prevent rapid conduction of heat through the sheet. The same logic applys for the blanket->quilt ordering.

It’s the one that goes on the bed.

I’d tell you, but then they won’t let me into Fight Club.
[sub]Oh, wait, I shouldn’t be talking about this. Forget I said it.[/sub]

Why the hell would you have the sheet on the outside?

Huh. I’ve found that it always helps to layer the heaviest blanket on top.

I like a lot of blankets on me, so I go:

Top sheet
then two of my old comforters (that were bedspreads, at one time).
THEN I add an afghan that my mother made years ago
And then an even heavier afghan that my grandmother made.

I find that sheets help because they’re nice and smooth and soft, whereas the blankets are kind of older and rough. Sheets feel good against one’s skin.

I call that a blanket. If it’s on the bed to keep you warm, it’s a blanket. Quilts are blankets. Thin woven cotton things with satin binding tape are blankets. The big fluffy microfiber thing I have on my bed is a blanket. Blanket blanket blanket. Wow I just made “blanket” stop looking like a word!

I also grew up in a house with no top sheet, just the fitted shit on the bed. I do not feel significantly warmer nor colder whether I follow my own use of just a blanket, or Gunslinger’s use of a top sheet underneath.

He explained that in the OP. He thought it made better insulation that way. That’s what this whole thread is about.

Did you use a duvet? A duvet is like a comforter (the big puffy blankets–I grew up calling everything a blanket, too) but with a removable cover that can easily be washed. If so, where did you get it? I’ve only seen them in Europe. If not, did you have stinky, smelly blankets? Or matted, threadbare ones (from overwashing)?

I’ve never, in my nearly 50 years, heard of a sheet over a blanket. Might it be a regional thing?

First a bed sheet or fitted sheet over a matress pad.
Top sheet to trap the warm air around the body.
Next for the most comfort in cold bedrooms would be an electric sheet with individual (2) temperature controls. Unfortunately these are not longer manufactured as far as I have been able to determine. Consumer Prod. Safety Comm. or some such nanny agency have a fear that I might be elecrocuted in my sleep.
Next blankets and or comforters as needed.

If you can keep the ‘stack’ close to your body instead of stretched across the bed like a tent over you and your spouse you will find it will warm up quicker and keep you toasty all nite long.

If you don’t like the initial shock of cold sheets try to find some ‘blanket sheets’ which are warm to the skin as they are thin, soft, and easily washed.

So, Tyler, what’s a duvet?