tealight

lämpökynttilä; tuikku A small, typically circular candle encased in a thin metal cup, so that it liquefy liquefies completely when lit and burns as a wick immersed in molten wax.
2004, Staffordshire Fire and Rescue Service http://www.staffordshirefire.gov.uk/ccm/content/press-releases/2004/april-2004/tea-lights-pose-potential-danger.en

Candles and tealights can be hazardous and must be used in accordance with any instructions.