New Delhi, Jan. 6 -- Room heaters are easy to trust because they don't look dangerous. They're small, familiar, and usually quiet. You plug one in, the room warms up, and within minutes it feels indispensable. As chairs drift closer and your feet edge toward it, someone jokingly says, "Don't turn it off." And just like that, it becomes part of the room rather than an appliance doing serious electrical work. That comfort is where most problems start.

The first thing people stop noticing is distance. A heater that began the season sitting neatly in a corner slowly inches closer to the bed, the sofa, the curtain, the laundry stand. Not because anyone decides to be careless, but because warmth feels better when it's closer. The problem is th...