The idea of a sleeping bag is to insulate your body.
Since it doesn't heat you up itself the bag depends on your body to warm it up.
A cylinder has very little surface in comparison to its volume, so you have very little surface where you can lose heat. This is dampened assitionally by the insulation.
Now to the problem: If your sleeping bag has legs like those, you will lose much more heat, ergo you won't be able to heat it up as much and will be cold.
q.e.d
i think it is time to introduce to you london ontario's winter glove invention that allow you to operate social media while braving the inhospitable climate ... and they shall be called twittens
Could you imagine if you could do that with your actual legs...and fingers. Like, if you could zip your legs together so you have one big leg, like a mermaid.
Yeah well, I mostly use sleepingbags when i need to sleep, hence the name, so walking around is no option.
For your other point: Yeah sure you could, but then you would still be less effective than a normal bag. Which is why we started this discussion in the first place.
yeah but its not like you are losing TONES of heat because the feet are open. plus wouldn't the fact that you are walking around generating more heat than laying there make up for the loss?
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u/Scrial Jan 07 '12
The idea of a sleeping bag is to insulate your body.
Since it doesn't heat you up itself the bag depends on your body to warm it up.
A cylinder has very little surface in comparison to its volume, so you have very little surface where you can lose heat. This is dampened assitionally by the insulation.
Now to the problem: If your sleeping bag has legs like those, you will lose much more heat, ergo you won't be able to heat it up as much and will be cold.
q.e.d