If any reader is not familiar with this, when a person gets a hole in their thorax (chest above the diaphragm and "gut"), they can have trouble breathing because as diaphragm moves to draw air into the lungs, it just draws air in through the perforation (bullet hole) instead. Entry and any exit holes have to be sealed for breathing to function. Seals can be improvised with plastic bags and duct tape -- that's what I'd do in a non-firearm specific wilderness backpacking kit -- but if you have a kit specifically for the range, you'd want proper seals. The vented ones work best -- HYFIN VENT CHEST SEAL TWIN PACK . Of course, I also recommend training to use them, and training relevant to other types of gunshot wound trauma.
