Survival Bivvy Bags

What a bivvy bag is

A bivvy bag is a waterproof bag you lie in, with no poles and nothing standing over you. There are two quite different kinds in this range, and it is worth knowing which you want before you buy. An emergency bivvy is a light sheet of reflective film you carry in case you are caught out, and hope never to open. A bivvy cover goes over your own sleeping bag to keep it dry and clean when you sleep out on purpose, on a hilltop, in a shelter or under a tarp.

Emergency bags, tube tents and bivvy covers

• Emergency sleeping bags are the biggest group here: aluminium-coated PE or mylar film, in orange, green or camouflage, which the makers say reflects up to 90% of your body heat. See emergency shelters.
• A two-person tube tent of mylar, held up by a rope tied between two trees, for when there are two of you. See foil and reflective shelters.
• A Tyvek bivvy cover made from DuPont Tyvek, white, which its maker describes as waterproof and breathable. It is a cover only: the sleeping bag is not included. See tarps for a roof to sleep under.

Breathable or not, and why it matters

This is the biggest difference between the bags. Mylar and PE film do not let moisture through, so the damp from your breath and body builds up inside on a long night, and your clothes and the inside of the bag get wet. That is fine for a few hours in an emergency, when staying out of the wind matters far more. The Tyvek cover is described by its maker as breathable, with a ventilated design to cut condensation, which is what you want night after night over a sleeping bag you need to keep dry.

Length, width and the head cover

Check the size against yourself in your clothes, or against your sleeping bag. The orange emergency bag here is 213 by 91cm, and the green and camouflage ones 200 by 120cm. The Tyvek cover comes in two types: Type A is 180 by 145cm with no head cover and weighs 135g; Type B is 230 by 90cm with a head cover and weighs 200g. Packed, both are 16 by 8.5cm. The smallest emergency bag folds to 6 by 6 by 8cm and weighs 110g.

Questions people ask about bivvy bags

Can I use a bivvy bag instead of a tent?

On a dry, settled night many walkers do, often with a tarp overhead to keep rain off their face. In wind and steady rain a small tent is far more comfortable. See 1-man tents.

Which colour should I choose?

Orange if you might need to be seen: several makers describe it as helping rescuers find you. Green and camouflage are for blending in.

How long does delivery take?

Delivery is included in every price and tracked to your door. Each product page says when that tent usually arrives, so check it before ordering for a set date.

More to look at

• Emergency shelters
• Tarps and tarp shelters
• 1-man tents
• Hammock tents
• Groundsheets and footprints
• Aluminium foil tents
• Guide: Backpacking and trekking tents
• Guide: Wild camping in the UK: where it is allowed