How do you give rescue breaths to an infant without a barrier device?

To give rescue breaths to an infant without a barrier device, first ensure the infant is on a flat, firm surface and assess for responsiveness. If the infant is unresponsive and not breathing, gently tilt their head back slightly to open the airway, and cover their mouth and nose with your mouth. Deliver two gentle breaths, each lasting about one second, watching for the chest to rise. Be careful not to provide too much air, as infants' lungs are small and can be easily overinflated.