While I carry a AMK Heatsheet or Bivy in my pocket, I really don't have much confidence in either. Always in my pack and both of my dogs packs are the Sportsman's Blankets, they are tough and they work and cost around $13. For years I've used them silver side out in the warm weather at dog events to cover crates and keep the dogs cool. They last for years and are well worth the money. The only downside is they aren't pocket able.