Final answer:
Rescue breaths should be administered over approximately one second to facilitate effective ventilation.
Step-by-step explanation:
Rescue breaths should be given over a period of about one second per breath to ensure adequate ventilation without over-inflation of the lungs. When providing rescue breaths (be it during CPR or other rescue situations), it is important to allow for sufficient time for the lungs to fill with air, which assists in oxygenating the blood before it travels to organs and tissues. Quick breaths may not deliver enough air, and too slow or forceful breaths could damage the lungs or cause air to enter the stomach.