How does water buffer a sudden drop in temperature?

Question

A property of water is that it is slow to heat and cool. According to my biology book, some energy from an increase in temperature would spent breaking hydrogen bonds, so that temperature does not rise too fast - helping a cell to maintain homeostasis. As far as I can tell, this answer does not explain how a drop in temperature would be slowed down by water in a cell. How does water slow down heat loss? Is it just because it is difficult for the heat that is already inside the cell to leave?

Answer 1

Water's hydrogen bonding means that a great deal of energy is required to break the connections between one water molecule and the next. It takes a great deal of energy for a water molecule to evaporate. To put it another way, liquid water can exist over a wider range of temperatures than many substances. This means water is a heat sink. It accepts energy when the environment is warm (energetic), but still stays liquid. When the environment cools, energy moves the other way, from the water to the environment, warming the environment. The energetic water can release a great deal of energy to the environment without freezing. This ability of water to act as a "bank" of sorts, accepting and dispersing energy without changing state is what lets water play an important role in maintaining steady conditions (in you and in the Earth).