Final answer:
Warning devices must be placed in areas where there is potential for extreme physical danger or uncertainty over whether a serious fire or hazard awaits after an alarm. These devices serve to alert individuals of potential dangers and allow them to take appropriate action to prevent harm.
Step-by-step explanation:
Warning devices must be placed in areas where there is potential for extreme physical danger or uncertainty over whether a serious fire or hazard awaits after an alarm. These devices serve to alert individuals of potential dangers and allow them to take appropriate action to prevent harm. For example, in public places, such as schools or shopping centers, warning devices like automated external defibrillators (AEDs) are often installed. AEDs provide verbal instructions to guide individuals in using them during cardiac emergencies, helping to save lives.