If I don’t feel any pain, I will be very happy. Because if I fall down or get punched, I won’t feel anything! But when I get hurt really badly on my back, I won’t know. If it’s bleeding, I could lose a lot of blood and could die. However, if someone creates a jacket that senses pain, it could help these kinds of people. How does it work? When a person bleeds, loses a layer of skin or falls down, the jacket detects it and alerts the person by making a sound.