Severe chest pain or pressure, especially if it radiates to the arm, jaw, or back Severe shortness of breath or trouble breathing Sudden weakness, numbness, or drooping on one side of the body Sudden confusion, trouble speaking, seeing, or walking Severe head injury, especially with fainting or confusion Seizures lasting more than a minute or not stopping Heavy bleeding, deep wounds, or serious burns Choking, stopped breathing, or electric shock Severe allergic reaction with swelling, hives, or difficulty breathing High fever with stiff neck, headache, or unresponsiveness Possible broken bones, especially if the bone is protruding through the skin Poisoning or overdose of medications, drugs, or alcohol