I initially purchased these to place on the ends of my Pop-Up camper as a sun reflector to help keep my camper stay cool. Once I got them, I realized that they were an excellent item for my B.O.B. These are 5 x 7 sized spaced blankets, that are very heavy duty. But more important, they are not the cheap things you buy at Wal-Mart for $2 that are light and flimsy and noisy as heck. Mine have survived repeated beatings in downpours and high winds strapped to the pop-outs of my camper. There are grommet holes on all four corners and along the edges. This makes it easy to secure the tarp down or to make some type of shelter out of it. One side of the space blanket is colored. You can get bright colors that would help in signaling and spotting you. Or, you can get one in OD green which is what I have. I figure if I want to signal someone, I'll use the shiny side of the blanket or my signal mirror. The other side is the shiny stuff that is designed to reflect your body heat back to you if you would wrap up in it. Being heavy duty, you could wrap up in it during a rain storm, and walk thru the woods without fear of it being torn to shreds like the light weight blankets that most people have. Not only would it reflect body heat, but it will act as a great rain and wind shelter. If you build a shelter out of it. By putting the shiny side down toward you, it should also reflect heat from your fire back to you helping to keep you warm. Being 5 x 7 in size, you could build a nice shelter and still use a section for ground cover if you are by yourself. Don't let the size and weight scare you. It isn't that heavy and what weight it does have, it more than makes up for it with it's strength, size, and multitude of uses. I highly recommend these blankets. I have one in each B.O.B. One in each car as an extra protection if we would get stuck and have to spend the night in a car that won't run and the temps are dropping fast.