Its not the cash value of the heatsheet that I am protecting, its the life saving value.

When I need it, I want to make sure its in top notch condition. Natural shelters are nice, but in a "I need a shelter right now" situation, the heatsheet is tough to beat for its size and weight.

My pack has taken some crashes over the years, and I consider a space blanket or whatever you decide to carry for shelter one of my more important items. So, I would like to carry it protected.

I am considering switching over to the bivy, and I think one of those tubes would be perfect to carry it and some other small survival gear.