When approaching an emergency scene, follow the internationally standardized trauma algorithm: * **Danger:** Ensure the scene is safe (check for moving traffic, fallen electric lines, or fire hazard) before approaching. * **Response:** Gently tap the casualty's shoulders and ask loudly, 'Are you okay?' * **Catastrophic Hemorrhage (C):** Immediately control spurting arterial blood using direct firm manual pressure or a commercial tourniquet placed 2–3 inches above the wound on the extremity. * **Airway (A):** If the patient is unconscious, open the airway using the 'jaw-thrust' technique without tilting the neck if spinal trauma is suspected. * **Breathing (B):** Look, listen, and feel for chest rise and breath sounds. * **Circulation (C):** Check carotid pulse. If absent, initiate cardiopulmonary resuscitation (CPR) with 30 chest compressions followed by 2 rescue breaths.

Common home first aid mistakes cause severe secondary tissue necrosis: * **Burns First Aid:** Cool the burn under running cool tap water for 15 to 20 minutes immediately. This halts thermal progression into deeper dermis. Never apply toothpaste, butter, flour, or ice to burns; these trap heat and cause bacterial contamination. * **Electric Shock:** Switch off the main power supply breaker before touching the victim. Use a dry wooden stick to separate the victim from live wires. Check pulse immediately and begin CPR if heart has arrested.