BTW, it terms of improvisation.
always seemed to me that pieces of thick cardboard were really helpful. but you need them to be long. maybe 3 feet long. you can bend cardboard (down the axis, lengthways), and use duct tape to wrap it. and it's excellent for building splints very quickly. The nice thing about cardboard - very easy to cut with scissors. So you can shape it - to your own purposes. also, if you don't use it for EMT purposes, you can always burn it as fire material.

the main disadvantage. it's useless if it gets soaked with water. if there was such a thing as "water-resistant" cardboard strips, it would be nearly ideal.