The fact that the resupply crates that you can find at your team's spawn location in most game modes will heal your character when used to perform a full resupply is far from obvious. A player can play the game for 100 hours or more before they really notice the faint bloody edges of their screen going away when they perform a full resupply, or before reading the 1 loading screen tip in the game that tells you that the crates offer healing, so it's safe to assume that the percentage of players who know about this function is much lower than it should be. This becomes a problem when players on low health unknowingly miss out on free healing and proceed to die in shootouts that they would have lived through if they had full health, to the detriment of their teams.
This problem can be easily fixed by adding a colored medical cross like the one below to the resupply crate icon: