Check the smoke detectors.

Unfortunately, not everyone knows how smoke alarms work, or how to test to see if they are even working in the first place. 

All it takes is a couple of minutes to Google how to check your smoke alarm and go do it. It's really simple! Besides, you checking that smoke alarm could be the difference between things going up in flames or not! 

Ideally, smoke alarms want to be checked once per month, and the batteries replaced every two months. Get yourself into a little routine, and soon it will become natural to do this deed over and over again. 

Cost benefit to society 

Fires cause vast amounts of damage to buildings. The costs to recover and repair damage caused by fires can be huge. This cost benefit calculation is based on the average cost of a fire in a domestic building (such as a house), minus the averege price of some new smoke alarm batteries.