During the winter, air temperatures in the northern united states can remain below 0 c months; however, the fish and other animals living in the lake surive. the property of water that makes this possible is

When the water gets cool, the formation of hydrogen bonds holds the molecules of water in its position in the form of solid. This form of water is called ice. The freshwater gets denser with cooling until it attains s temperature of 4 degrees Celsius. Ice gets less condensed as it cools, that is, when the temperature falls even more.  

This takes place as the expansion of water takes place due to freezing. As the mass stays similar, however, the volume of the solid is more, ice is considered less dense in comparison to liquid water, thus, it floats. Due to this characteristic, the water bodies like bays and lakes get freezes at the surface.  

This characteristic permits the fish living in ponds and lakes to thrive during the winters. The ice, which freezes on the surface shields the water underneath it, thus, helping it to remain warmer.  

your body is trying to warm itself up. or more precisely, sensors in your skin send messages to your brain to generate heat to your body.