In a medical emergency, rescue workers can help a patient breathe using a squeezable bag with a face mask called the Ambu bag. Before its invention, rescue breathing attempts were often futile. Those efforts, including mouth-to-mouth resuscitation, caused more problems than they solved.

Seat belts and airbags can help to prevent serious injuries in a car accident. At the same time, these protective devices can create physical problems themselves, report doctors at MedStar Emergency Medical Services. Seat belt injuries may not always seem immediately obvious.