Lest it be lost in all the leftist blood-dancing over the attempted assassination of Representative Scalise, note that his comrades worked to save his life, including improvising a tourniquet.
Wow: Colleagues Rushed to Save Scalise’s Life - Cortney O'Brien
Since you can't count on having a veteran combat surgeon handy if and when the unthinkable happens, you should consider adding a trauma kit to your carry preparations.
PDF: Optimizing the use of Limb Tourniquets in Tactical Combat ...
tourniquets save lives at DuckDuckGo
Buy one, or more, and learn to use them.
I have a bunch of SOF-T Wide models, because group buy.
Tactical Medical Solutions | Training Resources
Here's one on improvising a tourniquet with a triangular bandage:
NOTE: It is highly recommended that you DO NOT limit your training on these essential items to watching a couple of YouTube videos, even if they are posted by an unimpeachable source.¹
In addition to TacMed, other good sources of equipment and information include Chinook Medical Gear, Inc and Imminent Threat Solutions.
Training is available through Insights Training: Tactical First Aid Training and Dark Angel Medical, among others.
Previously on The Cluemeter²:
1. Not that I consider myself unimpeachable on this sort of thing.
2. As I typed this I heard it in the voice of the announcer for the Adam West Batman series...