In which situation is it safe to use an AED?

Using an AED is safe only when the patient's chest is bare. This ensures that the pads can make proper contact with the skin for effective delivery of the electrical shock. Clothing or any other barriers can prevent the pads from functioning appropriately, increasing the risk of the shock not being delivered effectively.

Using an AED on a patient in water poses a risk, as water can conduct electricity and create a danger of shock to the responder or others nearby. A metal surface may also create a safety concern unless no part of the patient is in contact with the metal and if the environment is otherwise controlled, however, the safest choice involves ensuring immediate and direct contact with the skin. Even when a patient has a pacemaker, it's important to ensure there are no obstructions, and the chest should still be bare for optimal AED function. Thus, having a bare chest is essential for the use of an AED.