I have a question

[Timinator]

I haven't been able to get any real winter action with my gear until recently. I Just went up to vermont for a weekend and decided to do some temperature testing. It was supposed to be 4 degrees that night and I was in a 15 degree bag. I not only kept my head out but I ended up taking off all my layers and opening the inner fly a bit to let out condensation. Am I just a warm sleeper or is there something I'm missing because I cant wrap my head around it.

[jburgasser]

Were you ijn a tent with rainfly? I think that tends to keep some heat in.

Ickybod

[Timinator]

Yeah I was in this http://www.hilleberg.com/home/products/soulo/soulo.php How much warmer would a tent like that keep me? I did have the inner fly open like half way.

[coach lou]

Yeah I was in this http://www.hilleberg.com/home/products/soulo/soulo.php How much warmer would a tent like that keep me? I did have the inner fly open like half way.

This is the science of an insulating layer... the space between the cold wind of the fly and the inside of the tent warms and helps to raise the temp of you inside that layer of warmed air....did that make any sense...it's still early.:D

[jburgasser]

Nice lookin tent. I don't know degrees-wise how much warmer it would be. I have a 1-man tent, but it is the low, long type. Not the tall type like yours. I know that inside there it is much warmer than the the outside air when I crawl out in the morning. Maybe it wasn't 4 degrees like you said it was supposed to be. Do you carry a thermometer? I have one attached to my pack's shoulder strap, just for curiosity.

Ickybod

[Deadeye]

A tent beenfits in two ways - first, it does trap some heat, and second it provides a calm environment, so your bag & pad are as efficient as they can be

[Slo-go'en]

If it really went down to 4 and you were toasty warm in a 15 bag, I wouldn't complain :)

Were you staying somewhere, had a good meal and then went outside just to sleep? That could make a big difference than hiking all day, and being tired and a little damp with a less than optimal meal early in the evening.

[FarmerChef]

Do you carry a thermometer? I have one attached to my pack's shoulder strap, just for curiosity.

Ickybod

Same question here. Predicted temperature and actual temperature can vary substantially based on elevation, land contours, heat sinks, etc. If it really was 4 degrees and you were plenty warm, consider yourself blessed and enjoy! Before you take that to the bank though, I would recommend getting out on an out and back or a loop hike that lets you hike all day and sleep out at night. Make sure to only eat what you would realistically have with you to eat on your worst day on the trail and see if you still feel comfortable.

Also, what other layers were you wearing to bed?

[colorado_rob]

Many of the winter/cold experts on here will disagree, but I find that both myself and my wife (a chilly sleeper) are comfortable in a good 4-season tent, properly ventilated, down to about 10-15 degrees below our bags' ratings, so a 15 deg bag would be perfect for me in 4 degree temps. I use a -25 deg bag very comfortably down to -40, for another example.

I want to reiterate: this applies only in a good 4-season tent, like the one you have (maybe the best 4-season tents made). It also relies on a good sleeping pad system (I use a double-pad system, a thin closed cell under a reasonable insulated blow-up pad).

So who knows if it was really 4 degrees for you, so as others have said, might be nice to have a thermometer ( a low-recording one) with you so you can gauge your bag's warmth more accurately.

[Hosaphone]

I've looked a bit at that tent. In this review, the guy reports having a ~10-15 degree temperature difference between outside and inside of the tent. I'm sure there are a lot of factors and it might be lower or higher at very cold temps, but fwiw:

http://www.youtube.com/watch?v=yEfmzI1tO6I