I've used the Thermolite as a lightweight sleeping bag for backpacking in July. I brought along a fleece sleeping bag liner which is light and comfortable that I put into the Thermolite. I slept great. The Thermolite is reusable, and it doesn't crackle and rustle all night like a space blanket. I don't know that it's as strong as a regular sleeping bag, but I haven't had any problems with splitting, cracking, tearing, etc. I generally carry the Thermolite on colder weather day hikes and a simple space blanket bivvy on warmer weather day hikes.