Bivouacking: All you need to know about equipment, bivouac sites and other tips

Steffi, what attracts people to spend a night in the wilderness without a roof over their head – of their own free will?
First and foremost, of course, it’s to do with getting up close and personal with nature. Tents and huts protect you from the elements, but they also keep them at bay. When you’re under the open sky, you can interact with nature directly: it’s a great feeling! Plus you’ve got a lot more freedom in terms of where you spend the night – when you come across a nice spot, you can just stay there and get your bivouac out. Another benefit is that you need to carry less weight, as you can leave your tent at home.

So, what do I need for a night under the stars?
You need a sleeping bag and a sleeping mat, as a minimum. If you’d like a more comfortable set-up or the weather looks changeable, you should also take a bivy sack or tarp, plus a cushion, pyjamas, a headlamp and, of course, food.

Taking each in turn: it makes sense to opt for a sleeping bag with synthetic fibres, right? Because I’m exposed to the elements without any protection?
You’re right that synthetic fibres are less sensitive to moisture as they’re less absorbent, and that they provide warmth even when damp. I still prefer down for sleeping bags, though: its ratio of warmth to weight is simply unbeaten. I also find it a more pleasant atmosphere for sleeping in. And even with a light bivy sack to protect against moisture, it remains a lighter, more compact option than most synthetic sleeping bags.

Why wouldn’t I just go for a sleeping bag with a waterproof exterior?
If you’re really only going to be sleeping outdoors, this is an option. However, these models are often very heavy and bulky, so a bivy sack or tarp is usually the better choice – as you only use them when you need to and they barely weigh a thing.

Are bivy sacks anywhere near breathable enough? 
That depends on the material. There are models with Gore-Tex or other membranes that are hugely water-permeable and let the moisture from sweat escape while still offering reliable protection against wind and dew. Simpler, cheaper emergency versions focus on offering basic rain protection. But regardless of whether you use a bivy sack or not, I always pack a tarp so I can be sure that – whatever the weather – I’ve got somewhere dry to get changed, cook and store my equipment.

But then you’ve lost your lovely view of the night sky...
The tarp is just a back-up: I’ll sleep under the stars whenever the weather permits, of course. But even if you do have to put a roof over your head, you don’t need a perfect base underfoot (unlike with a tent) and you’re still much closer to the elements. Spending a stormy night under a tarp can be a very intense, impressive experience.

The temperatures get quite chilly overnight in the mountains, even in the summer months. How can I ensure I have enough insulation beneath me?
A good mat is just as important as your sleeping bag: the filling in your sleeping bag is squashed together when you lie on it, meaning that these areas offer little protection against the cold. Mats come in different temperature categories, too. Models with a synthetic fibre or down filling are ideal for bivouacking: they’re just a little heavier than purely inflatable mats, but they offer fantastic insulation on cold ground. When you’re buying one, make sure the material is durable. Having the lightest mat is useless if a spiky pine needle is enough to let the air out of it. If you want to be on the safe side, take a light protective film with you to use as a base. 

It’s time: I’m finally on my adventure and the day is slowly coming to an end. How can I find the perfect bivouac site?
Your safety should always be your top priority for your bivouac site: is the site protected against lightning strikes, rockfalls, avalanches and floods? True, having a source of fresh water makes cooking and washing easier, but even little streams can suddenly swell and burst their banks if there is heavy rain in their drainage basin. Apart from that, make sure you’re sheltered from wind and think about the angle you’re at: if you want to wake up with the sun in the morning, you need to have an unobstructed view to the east. Plus, keep enough distance from managed huts. If you still want to stay near them, let the hut manager know, give them a small amount of money in exchange for the use of their toilet facilities or buy something from them – that way, you protect the environment and create acceptance.

Am I allowed to bivouac wherever I like?
Sadly, the legal situation in Switzerland is a bit of a patchwork. Generally speaking, you’re not allowed to bivouac in the Swiss National Park, in nature conservation areas and in no-hunting zones. If you want to bivouac on private land, you need to seek consent from the landowner. Otherwise, if you’re above the tree line, you’re generally permitted to set up an emergency bivouac. The ‘Camping and bivouacking’ guidelines issued by the SAC offer a good overview. But, as always, the key rules are: take nothing with you other than your memories, leave nothing behind other than your footsteps.

I suppose it’s a good idea to do some planning before setting off. What do you need to bear in mind?
For your first bivouac adventure, pick a period of good weather when storms are unlikely – ideally in the summer. Before you leave home, look for suitable spots using a map that’s as detailed as possible (scale 1: 25,000) and plan your route so you’re not spending ages searching for a bivouac site on exposed terrain as evening falls.

Do I need to trim down the amount of food I pack, too?
If you’re only going to be out for one or two nights, you can pull out all the stops: a fire-cooked pumpkin soup or a three-course meal with fresh ingredients, prepared on your gas stove. If you've planned a longer trip, I recommend freeze-dried trekking meals; you can also make them yourself.

So there’s no problem with having an open fire in the mountains?
Only if there’s no risk of a forest fire and there are no fire bans in place! In principle, you should always use a fire pit if one’s available and not start a fire so enormous that the fire brigade down in the valley turn up. I personally don’t want my bivouac to be too conspicuous, so I usually don’t make an open fire at all. Instead, I prefer to take my ultra-light wood carburettor stove with me, so I’m not dependent on gas or petrol. You only need little fragments of wood (which I collect en route) to get it going.

I need to pop to the loo before I go to bed. Do you have any tips?
Do your business away from bodies of water and bury any waste. Biodegradable soap isn’t just for cleaning your body: it’s also great for laundry and dishes. Multi-purpose bags also come in handy – use them to easily carry empty jars or dirty washing back to civilisation, without any odours escaping.

What do I need to bear in mind in terms of clothing?
Whenever you head off into the mountains, you should have a dry set of spare underwear with you, as a minimum – and bivouacking is no exception. I recommend lightweight merino wool for your first layer: its fibres are heavily crinkled, creating insulating patches of air. This also means there are fewer points of contact with the skin, creating fewer cold bridges. Plus, wool keeps you warm even when it’s damp, it gets substantially less smelly than synthetic fibres and it’s less vulnerable to sparks that fly off your campfire.

It’s time for bed! Should I just roll out my sleeping bag, crawl in and drift off?
You’d be better off giving your sleeping bag a bit of time to fluff up: it can only insulate you to its full effectiveness once the down has spread out as much as possible after being squashed up in its packing bag. Also make sure that your sleeping bag doesn’t get damp, as lots of dew forms at twilight. Above all, though, you shouldn’t get into your sleeping bag when you feel cold. Contrary to what many people think, a sleeping bag doesn’t warm you up: instead, it just insulates the heat that’s already there. So, you’re better of jogging around the camp three times if you’re feeling the chill. And you can quickly turn your drinking bottle into a cosy hot water bottle by filling it with warm water.

How should I store my clothes, shoes and equipment overnight?
Everything that needs to stay warm and dry – in other words, your clothing, socks, electronics and possibly gas cartridge – should go in your sleeping bag with you, with the rest being stored in your backpack. You can also put your shoes under your sleeping mat as a replacement pillow.

What should I do if it suddenly starts to rain overnight?
A bivy sack is all you need if it’s just a light drizzle. Otherwise, it takes seconds to use a bit of cord and your hiking poles to hang the tarp over your bivouac site – even in the middle of the night. In any case, it’s worth choosing your sleeping spot with care: when it rains, little lakes form quickly in dips and the cold can really set in here, too.

How do people normally welcome in the new day after a night of bivouacking?
Ideally, with a freshly brewed coffee! My espresso-maker doesn’t weigh much, but it’s a real treat – and, after all, I’ve got more room in my backpack for little luxuries because I’m not taking my tent with me.