If you must go out on the ice, the Coast Guard says it is wise to go out only on ice one has already tested and only during daylight hours. The Coast Guard also cautions against driving skimobiles on the ice of the Gulf of Finland.
Because of temperature fluctuations in recent days, much of the ice cover is uneven and porous, formed by slush refreezing. Such ice can bear only half the weight of normal smooth sea ice.
"Areas of thin ice, in sounds and where there is a current, can thaw on a sunny day and allow the water to absorb heat. Cold night temperatures may then create only a thin film of ice that will give way under someone walking on it," Jouni Vainio, a ice expert at the Finnish Meteorological Institute, explained to Yle.
The Coast Guard is also reminding the public of the risk of hypothermia even if one successfully makes it out of the water after falling through the ice.