Only use the heater for what it has been designed for . Don't use it as a clothes dryer unless it has been specifically designed for that purpose. And then, make sure you hang the clothes on the appropriate drying racks and keep them at a safe distance. Never place your heater close to curtains or other flammable material. Keep it at least one metre away.
Heat can build up quickly to the point where curtains and furnishings can ignite.
If the heater is switched off, don't turn it to face walls or furnishings as it could later be turned on by mistake, especially if it has a thermostat that automatically turns on as the room gets cold. With older heaters, check for anything broken or missing and signs of scorching, melting or blistering. Listen for any unusual noises or sounds. The smell of smoke or fumes suggest the heater is overloading or overheating. If necessary, consult a qualified service person.