Author Topic: getting cold whilst bivvying  (Read 1186 times)

getting cold whilst bivvying
« on: 30 June, 2021, 06:13:47 pm »
last night I had a great evening cycling up into the peaks, bivvying and then cycling back in the morning.  I had 2 questions though.

I have an appkit Elan divvy and a Pipedream 200 sleeping bag.  Last night was warm when I set off and I probably under thought.  Edited. I do have a thermarest neolite and did not feel strike through was the problem.

I was in cycling shorts, base layer and socks when I got into the bag and I was cold.  I put on arm warmers and my insulated Rapha waterproof but was still not warm

The overnight temperature probably was around 7C up there.

Was I underdressed and would you have normally taken another layer of clothing or is my bag too thin for most Uk conditions and I should upgrade?  I do not want to sendup with panniers stuffed with loads of clothing (extra weight) if I should simply buy a heavier bag?

Also best inflatable pillow?

Kim

  • Timelord
Re: getting cold whilst bivvying
« Reply #1 on: 30 June, 2021, 06:32:21 pm »
I'd freeze my arse off at 7C in a bag like that, but I'm of the Butterfly school of insulation.  No mat?

Being cold when you get in the bag is a rookie mistake.  It takes ages to warm up if you're not moving around, and presumably there isn't much scope for wriggling in a bivvy (I'm firmly in the small tent camp).

Down jacket might be an alternative to a thicker bag?


As for pillows, my Decathlon 'Helium' one was the best I've come across (more comfortable than the now legendary Ajungilak), but I'm not sure if they're still making them.  I'm sure I wrote a review somewhere, but I can't find it.

Cudzoziemiec

  • Моя планета голубая, я люблю тебя и обнимаю
Re: getting cold whilst bivvying
« Reply #2 on: 30 June, 2021, 07:21:00 pm »
Definitely underdressed for 7C IMO. I wouldn't be warm in cycling shorts, base layer and socks at that temperature if active so I'm not going to be warm when trying to sleep. It's worth remembering that sleeping bag temperature ratings assume full clothing including a hat, as well as a mat with fairly high R value.

I'd second Kim's point about needing to be warm before getting in the bag. Also you could try a hot water bottle (warm water in a bottle).

I've never used an inflatable pillow, just use a jacket or something stuffed in a stuff bag. Or even in a pillow case!
Riding a bike through a city is like navigating the collective neural pathways of a vast global mind.

quixoticgeek

  • Mostly Harmless
Re: getting cold whilst bivvying
« Reply #3 on: 30 June, 2021, 07:32:24 pm »

The mistake many people make is being a bit chilled/cold when they get into the sleeping bag, and not being able to generate enough of their own heat. So, the thing to do is to boost your own system. You will need a stove, pot, an HDPE Nalgene bottle, a sock, and maybe a dry bag:


Fill the HDPE nalgene bottle with boiling water, place it in your spare sock (and optionally in a dry bag if you have trust issues), stick it in bottom of sleeping bag. One hot water bottle, one preheated sleeping bag. I carry a pair of 500ml bottles, (1000ml doesn't fit in my socks), I put one near my feet, one near my back. The extra bonus is that I have prewarmed socks for the morning, as well as able to make tea/coffee faster in the morning by using warmer water...

Don't use the polycarbonate ones tho, as the water cools it creates a vacuum. This will crack the polycarbonate as it's not flexible enough. The HDPE ones work great tho.

As mentioned also in the camping malarky thread.

Also note, your bag is rated for 7°C, meaning that some super human people in ideal situations will be warm enough in that bag at that temp. For that temp, a 0°C bag would be likely more comfortable.

The other thing to consider is that you slept in your cycling kit. This will have a sweat load. That will make you colder too. Carry dry clothing to sleep in. A merino base layer is ideal for this. Def carry socks to sleep in (I like seal skins for this).

As for the pillow, exped ul pillow - https://www.ultralightoutdoorgear.co.uk/equipment-c3/sleeping-bags-c21/pillows-c61/air-pillow-ul-p15212

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

quixoticgeek

  • Mostly Harmless
Re: getting cold whilst bivvying
« Reply #4 on: 30 June, 2021, 07:33:10 pm »

Oh, and carry a space blanket, if you do find you fucked up the forecast at some point, and it's colder than you expected, the space blanket can be a good boost.

J
--
Beer, bikes, and backpacking
http://b.42q.eu/

Re: getting cold whilst bivvying
« Reply #5 on: 30 June, 2021, 08:33:26 pm »
Put your insulated layers on as soon as you stop. Beanie on the head. Get in the bag after that, whilst still warm. Then get your evening meal / hot drink inside you. Try not to arrive at your bivvy sweaty. Rider slower to sleep warmer.

Re: getting cold whilst bivvying
« Reply #6 on: 30 June, 2021, 09:16:34 pm »
Thanks everyone. That I what I needed to hear. Nalgene bottle makes a lot is sense as extra water transport as well.
Need some full merinos and the Nalgene.

Re: getting cold whilst bivvying
« Reply #7 on: 30 June, 2021, 09:17:57 pm »
I feel you probably need a warmer bag, at least for overnight low temperatures going below 10° or so.

The Pipedream 200 has EN ratings Comfort=11°, Limit=7.4°, Extreme=-5.8°

EN ratings are as measured by an instrumented heated dummy, wearing a base layer, in the sleeping bag, in a cold chamber.
Comfort is the temparature above which the "average woman" would sleep normally
Limit is the temperature above which the "average man" wouldn't be shivering
Extreme is the temperature below which there's a risk of hypothermia

It's therefore not surprising that 7° was colder than was comfortable.
Individuals would vary a reasonable amount from "average", but once you've calibrated yourself in one bag, to find out roughly where your personal "good night's sleep" limit is, the ratings are a good guide.

Wearing stuff you'd still be carrying if your bag was warm enough may be enough, but carrying extra stuff to keep warm enough in the bag you've got will be heavier than carrying a warmer sleeping bag instead.

As noted, it takes a long time to warm up lying still in an only just adequate sleeping bag if you were cold to start with. It would probably be quicker to get up and warm up by going for a run, always provided you don't turn your ankle in the dark.



For pillows, I've found the Sea to Summit Aeros better than the Exped - a more face-friendly material, a modicum of insulation, and hasn't failed on me (yet).

Re: getting cold whilst bivvying
« Reply #8 on: 30 June, 2021, 10:19:57 pm »
Loads of good advice above - a couple of things I'd add is that layering can work with sleeping bags as well as clothes - a thin liner (cotton/silk/manmade) inside your sleeping bag can make it feel much warmer. Also, get your bag out to air and plump up as soon as you can when you stop - if you unpack your bag just before you get in it, you'll lose more heat through the crushed-up/flattened insulation to start with.
Back in the saddle :)

Re: getting cold whilst bivvying
« Reply #9 on: 30 June, 2021, 10:25:58 pm »
I'd put leggings and a fleece/jacket on.   I'd rather start warm and remove than get cold and try to warm up. 

Re: getting cold whilst bivvying
« Reply #10 on: 30 June, 2021, 11:03:00 pm »
AIUI, sleeping bag temperature ratings are done with a sleeping pad with an R rating of 4. If your pad has a lower rating, that could be part of the problem. The lower limit is supposedly the lowest temperature at which the so called "average" male can sleep through the night, although he will probably have to curl into a fetal position to stay warm. If you have less body fat than the average male, or if you were already cold when you got in the bag, there's a good chance that you will stay cold. Sewn-through baffles like your bag has are a known source of cold spots, right on the seams where the inner and outer layers of the bag are sewn together. A test dummy might not notice the cold spots, but a human being will. Letting the sleeping bag loft up for a while before you get in is a good idea.

I did the jacket stuffed in a stuff sack for years, but when I tried an inflatable pillow I was an instant convert. Like andrew_s said, the Sea to Summit pillows are excellent. Sea to Summit sleeping pads are good, too, if you want to upgrade to a warmer pad.

hellymedic

  • Just do it!
Re: getting cold whilst bivvying
« Reply #11 on: 30 June, 2021, 11:04:16 pm »
Are you underfed?

Forget low-carb and throw in a good mix of SUGAR, starch and fat.

Don't go to bed on empty!

Kim

  • Timelord
Re: getting cold whilst bivvying
« Reply #12 on: 30 June, 2021, 11:55:20 pm »
Loads of good advice above - a couple of things I'd add is that layering can work with sleeping bags as well as clothes - a thin liner (cotton/silk/manmade) inside your sleeping bag can make it feel much warmer.

Also means your hard-to-clean down bag takes a lot longer to get manky, especially if you're going to use it after riding without the benefit of a shower.

Re: getting cold whilst bivvying
« Reply #13 on: 01 July, 2021, 08:14:58 am »
Are you underfed?

Forget low-carb and throw in a good mix of SUGAR, starch and fat.

Don't go to bed on empty!
I've read of one regular bivi camper that drinks some olive oil before sleeping.
Never knowingly under caffeinated