Use combined stirrer/hot plates when you need both functions. The controls for the stirrer and temperature control look the same. Fires occur when the stirrer is only needed but the heat source is turned on by accident.
Newer hot plates are manufactured to avoid sparks, older hot plates have a spark risk due to the position of the "on-off" switch on the unit itself as well as the bimetallic thermostat, which can become corroded and create a spark hazard.
Do not heat a metal pan on a hot plate. It can damage the hot plate and even pose a shock risk.
When removing objects from a hot plate, use tongs or thermal gloves. The same holds true when pouring hot liquids.
Perhaps the most important thing of all is to remember to turn the hot plate off. Hot plates left on are the source of most fire related accidents.