This guys went on a frozen lake to have some fun. One of them makes a hole with a knife in the ice and when he light a match a strong flame is ignited, burning for for a few seconds.
How is it possible? The explanation is simple: the ice acts as an insulating layer, separating water from the external environment.
The flame is maintained by methane gas accumulation in the water, which most likely originate from a rotting corpse.