Health Boxes are green First Aid boxes. They are found in a Safehouse or during a mission. Health Boxes cannot fully fill your health meter. If your health is red (low) it could take two Health Boxes to fill your health meter. Health Boxes can be obtained by running over them. They will make a squishy sound as if you crushed them. During missions is the only time Health Boxes are NOT in a Safehouse. You cannot use a Health Box if your health meter is full. If you used a Health Box in a Safehouse and leave the Safehouse another will be back. That means you don't lose Health Boxes. Once one is used, (after you are far away from the Safehouse) another will be back when you return.