Every remote, rescue or wilderness first aid course Ive taken required equipment. Either Stethoscope, BP monitor, etc. No improvisation was taught. I have never seen any advanced equipment on any hiker or on any training course Ive done. So learning things such as improvising a latex glove into a CPR mask or using a baggy and duct tape to seal a lung would be a great course to do.
Ive seen one person carry a pressure bandage and Ive been the only one carrying a tourniquet in six years. Good name for a book wilderness medicine Macgyvering
Disclaimer: Im not advocating cutting a camelback tube and shoving it up someones nose just a very interesting lecture.