At its core plasma weapons deal damage like a flamethrower or any other incendiary device; all damage is inflicted through extreme heat, but as soon as the heat is off it doesn't do any more damage. Since any wound that a plasma weapon makes would be cauterized there wouldn't be any immediate bleeding if any. With plasma weapons it doesn't make sense that if you get hit in the arms or legs that it could kill you. If a soldier or civilian is the unlucky winner of a lethal plasma bolt, but it hits them in the arms or legs they should instead be knocked unconscious or stunned. Their endurance will determine how long they can hang on before they go into shock and die. Anyone you manage to heal in time wouldn't be getting up anytime soon but they won't die ether. It would be nice to have some chance of saving the civilians that wind up in the wrong place at the wrong time.