The utility has warned domestic natural gas consumers in parts of Finland to "be prepared" for any interruption in natural gas supplies to parts of the country.
Consumers are urged to ensure that wood burning stoves and fire places are in good working order and that fuel is to hand.
If I have understood correctly, Finland is 100% reliant on russia for natural gas, but this is far less serious than it sounds because natural gas is not used on a large scale and makes up only about 5% of total energy used.
Domestic heating is primarily from electricity or wood, with only a few thousand homes heated by gas. Larger premises use mainly electricity, and a minority use "black liquor" a by product that results from turning trees into wood pulp for paper manufacture.
Finland has a very high electricity use per head, but a low consumption of coal, oil, and natural gas.
https://yle.fi/news/3-12444751
"Installers and owners of emergency diesels must assume that they will have to run for a week or more"