Modern hand grenades are designed the damage tissue as much as possible without killing, the tungsten hook like fragments aren't designed to kill, they're designed to lodge in soft tissue which on it's own requires surgical removal. However to "spice" things up they are coated in phosphorus which burns the wound internally, which requires another specialized surgeon to remove them without causing massive tissue damage. The point of which is to drain the enemy economy.
Whats the most messed up thing you've learned lately?