Ordinary smoke alarms can only do this one thing
Fire safety is a chief concern for homeowners, and smoke detectors play a vital role in safeguarding your family. Despite that fact, smoke detectors have their shortcomings. To illustrate, they can only detect smoke, not extreme temperatures. When there is a fire in your home, you would not be alerted until the smoke rises to the smoke detector. While there are further telltale indications of fire -- such as a marked increase in warmth -- if there’s a lack of smoke, there is no triggered smoke detector.
What’s more, smoke detectors only sound the alarm when they encounter enough smoke. When a fire begins slowly, you may not be alerted until it's too late. Various smoke detectors utilize more than one sensor, meaning they will recognize smoke from both a raging fire and a more gradual burn. Then when they start beeping, it’s required of the resident to call the fire department after safely leaving the property.