In the current 0.45 stable/regular version your character will crouch if prone to execute the 'bandage' action. If while under cover being prone (Z) you try to bandage yourself, the character will go crouch, exposing the torso + head becoming an easy target to shoot.

Therefore I suggest you ENABLE the bandage action while being prone (Z) so in the future characters can bandage under cover.

UP VOTE pls