There’s a bit of scaremongering going on on the Wild Camping Facebook group at the moment.
It’s a closed group, so I won’t bother posting the link, but here’s the text;

SAFETY TIP FOR THOSE OF YOU THAT ARE PLANING ON TRYING BIVY
BAGS UNDER TARPS FOR THE FIRST TIME THIS WINTER
NEVER fully enclose your head in a bivy bag. Don’t matter that it says it’s
breathable. You may find that you die rather that just create condensation.
There have been many deaths from this practice of total enclosure.
A quick look around the internet and you will find documented cases of
deaths caused by total enclosure in bivy bags. The British Army tried to
hush up the fact that they had lost guys some years ago to suffocation in
bivy bags. The USA were quite open about there loses.
If you plan on trying winter in your bivy, just use a nice fleece hat to keep the wind out of your ears and the heat from escaping through your head. It’s also a good idea to take a thin full face balaclava. I use just a fleece hat but have been under tarps for the past eighteen winters so I guess I’ve found what works good for me. So if it’s your first time out I would say take the balaclava and maybe pack in a one man tent in case you find that tarp life is not working for you. The tent will save your weekend from being a wash out and will also serve as a security blanket while you try tarps. You can also use a 2ltr Platy as a hot water bottle if you poor toes are feeling cold. Just let the water go off the boil for five minutes before you half fill the bag.
So stay safe my friends and live to tell the tale and also have a condensation free sleep

I had “a quick look around the internet” as instructed and couldn’t find anything.
It looks like nonsense to me, possibly caused by confusion between CO from a stove, which is deadly in a confined space, and CO2 from breathing, which is not inside a breathable bivi bag.

yes

Nope i have not- how ever i dont do it cause im cold or its rainng but rather keep the midges off and out.

If there is one thing that the scottish referendum has taught me – facebook is a conspiriousy theorists most powerful tool – the idiotic masses will believe anything written on there.

no

I tend to instantly dismiss anything that has sentences in capitals, poor spelling and punctuation, and non-existant paragraphs as complete bunk.

I’m still alive, so it appears to be working as a strategy.

maybe

I feel faint and diz

I’ve woken up with what felt like the worst hangover of my life in one (a gore tex tunnel hooped bivi) after not a lot to drink, so there might be something in it

Assorted insects appeared to have drowned in condensation/sweat when I spent a night in one of those orange plastic bags, I don’t believe any were asphyxiated.

almost.

veg lasagne with veg side. (they wouldn’t sell me chips!!)

I have done a couple of times. Worst experiences of my lives.

good idea to take a thin full face balaclava

Don’t do this, it makes my hair hurt 🙁

USA where quiet open about there loses.

Fixed

It looks like nonsense to me

Why? The hyperbole might be nonsense but the basic premise makes sense. Having your head in a confined space (that is probably made from a waterproof material) without enough ventilation will probably make you dead. The original ‘bivi bag’ was a great big orange plastic bag and I was certainly taught not to put my head in it and that seemed reasonable.

Bivy bag with bug netting at the head area is the best solution imho. Bring a tarp if it’s going to rain. Having had bivies made of various materials, it seems totally feasible that someone could suffocate in many fully enclosed bivy bags…I mean, most of those fabrics aren’t *that* breathable.

I died in a bivvy bag once but I survived to tell the tale.

You may find that you die…

Is that like waking up dead? How does one find out that death has happened?

The original ‘bivi bag’ was a great big orange plastic bag and I was certainly taught not to put my head in it and that seemed reasonable.

I think getting into it feet first is the recommended practice.

I wouldn’t risk is Graham, you have a habit of getting the worst out of kit… 😯

PS: Unless I can have your chalet/cabin thingy

I’ve never slept in a bivvy bag* and I’ve never died, which provides evidence for the case that not dying is correlated with not sleeping in bivvy bags.

*well not a posh breathable one – I’ve slept in a Blizzard bag, but without fully enclosing my head

NEVER fully enclose your head in a bivy bag

Are there any other bag types I shouldn’t fully enclose my head in? I think a list should be compiled for all our safety.

I’ll start.

1. Ball bag

2. Hand bag

3. Colostomy bag

tea bag

Bag of worms

Ball bag

Hmm… I’ve always found them to be perfectly safe

Have you actually ever put your head in one though…?

thomthumb – Member
almost.

veg lasagne with veg side. (they wouldn’t sell me chips!!) 😀

It makes sense not to fully enclose yourself IMO. But it’s not the kind of risk you can actually get data on to fully understand how much of a problem it is

CO is a killer because it replaces oxygen in the blood, and your body doesn’t know this is happening. So you can die in your sleep without waking up.

However your cardiovascular system is well used to sensing too much CO2 in your blood – that’s why it steps up breathing when you exercise – and it’ll make you feel breathless and wake you up with feelings of suffocation and panic, probably.

Depends on the bag surely?
I have zipped up mine several times overnight. It’s a bit stuffy but I think I survived.
Mine is an elderly full Goretex one from the days before cost cutting resulted in the base being something like PU. Something less “breathable” ( I hate that phrase) may not be so good for you.
Snowdon Mouldings in about 1985 and its still going strong.

Have you actually ever put your head in one though…?

Often. Balls should be removed first.

Edit again.

Nothing I’m writing is suitably amusing enough to warrant a reply.

I’m going to get lunch instead.

You wouldn’t be able to breathe through a sealed goretex bivy.

Could a bivi bag double up as an oxygen tent to simulate altitude training 🙂

Cheers, Rich

To summarise my argument on the Facebook group;

Why don’t the manufacturers put a warning on the bags?
Why are there no media reports of it ever happening?

Look at all the warnings of death or serious injury if you don’t fit or use it correctly that come with any new bicycle component.
Look at all the media reports of CO poisoning from using stoves in confined spaces.

It just doesn’t add up.

It just doesn’t add up.

What doesn’t add up? No deaths, no lawsuits; no legislation, no warnings.

maybe the people are still in the bags and decomposing in remote forest spots. All the decomposition gases would make the bag expand and it would be a like a decomp human ravioli.

I was about to die in a bivi bag once but a light woke me up.

Needless to say I didn’t walk into the light but shouted at them to turn it off.