Interesting to see this thread come alive again.

I ended up purchasing a few AMK Heatsheet bivvys. A bivvy is always warmer than a blanket when you need it to be. Based on the material, you can sweat, but it is easily fixed by adding a strip of duct tape towards the bottom and making a slit for ventilation. This acts similar to the much better and functional AMK Thermo-Lite bivvy which has velcro sides for heat adjustment. I've used the Thermo-Lite on multiple occasions and it is well worth the investment. I have every vote of confidence in the Heatsheet bivvy, knowing it's limitations, that it can perform as I expect. If I need it as a blanket for any reason, a knife will take care of that.

Happy Hiking!

You could also pack 2 jumbo yard waste bags per person

I always include at least two Space Blankets in my gear and often a bivvy of the same material. My thinking is to use one as a ground cover or blanket and the other as a tarp. Having experimented with them in a variety of conditions I'm under no illusion that they'll keep my toast and comfortable but they can keep me dry, and perhaps provide that margin of survival. Also they can be used to make a Palmer Furnace provided I have the other associated stuff (and I do usually have a couple of beeswax tea light candles).

A very old thread indeed. A bit melancholy seeing OBG's post but in a good way.

Reviving old threads is quite often informative.

I carry an 2GoSystems reflective Tyvek tarp bivy (36" x 87") and a silnylon poncho tarp. https://ca-2gosystems.glopalstore.com/products/trifecta?variant=5897656453 I have tested the bivy with a wool anorak down to 4°C, no wind; that's the limit of comfort without addition insulation. The bivy is about the size of a loaf of bread 4"Ø x 9.5" and the poncho tarp is about 1/3 that size. It sorta fits into my 750ml cup/pot.

I also carry a collapsible hiking stick. ON it I have wrapped a 6-mil drum liner, 750-paracord, 36# bank line, duct tape and snare wire. The cork knob on the top screws off so that I can attach a camera or binoculars to it.

Space blankets are not blankets and should never be used as such. They are OK for an hour and then gather a ton of sweat from you body. Their main claim to fame is their low cost. AMK's more specialized reflective blanket/bivies are OK but the complaint I have of them is that they are too small for 70% of the population! (Sorry, AMK, but I am not a 150 lb weakling.)

Tarps are great temporary shelters and if made of silnylon are very compact. But they are much less convenient above tree line if you need something to tie off too.

I generally buy bigger space blankets. AMK and Titan both make versions that are much larger than the cheapos.

I always spring for the "2 person" size

I might just carry an umbrella and sit under that overnight; multi use, small and waterproof

Bothy Bags are popular over here (Europe). Come in various sizes from 2 person and up (Terra Nova make a 20 person one).

Here's promo vid for an inexpensive brand's version, but they demonstrate how they're used.

https://www.youtube.com/watch?v=2YWwR8XTsRE

My"core bag" (essentials that go on every outing) includes a SOL emergency bivvy and some sort of mylar blanket. The mylar sheeting is used to make some sort of leanto shelter and I tuck my weary bod into the bivvy with as much insulation as I can scrounge....

Total weight is around 5 oz.

...Or even a pair of contractor type trash bags (55 gallon)