this time of year, this time of predictable warmyness, what is the minimum people are using in a bivi bag?
im pressuming the bivi bag is important for dew, and on the off chance it DOES hack it down un-expectedly?
then again, you could substitute it for a tarp if the ground is likely to be dry??

anyone use only a liner?
1 season?

http://drj0nswanderings.wordpress.com/
^ interesting ideas

I’ve got a 600g ME down bag rated to +8 deg that’s plenty cosy enough for spring / autumn with frosy mornings, and I’ve used a fleece liner on it’s own with a bivi bag in the summer, with a light down gillet worn in it. Saves about 150g, so not really worth it unless it’s a really minimal overnighter trip.

If a tarp offers good coverage it’ll stop condensation forming on your bag, I’ve used a tarp and no bivi bag a few times in the summer. Mainly as my old bag is a bit too warm, an Alpine bag rated to -5. Aim for dry ground, use bracken etc to give a bit of insulation and bag protection, works ok.

At the risk of being completely useless…..define summer and how “warm” do you sleep? We were getting subzero nights a couple of weeks ago.

My current favourite is a Mountain Hardware Lamina 35. It’s synthetic so, in theory, not as light or compact as an equivalent down bag. However, it will be a better insulator if damp and is a lot more easily cleaned (dirty down loses a lot of loft/insulating power). Some folk go lighter and wear more clothes – that’s OK assuming the clothes remain dry.