Final answer:
Water's high specific heat requires a lot of energy to change its temperature, moderating environmental temperatures, and its density decreases upon freezing, allowing ice to float and insulating aquatic life.
Step-by-step explanation:
The two properties of water that influence temperature are its high specific heat and its density anomaly as it changes from liquid to solid. The high specific heat of water means it requires an unusually large amount of energy to change its temperature. This is why water heats and cools more slowly than many other substances, making it a crucial factor in temperature regulation for organisms and the environment. In contrast, most substances become denser when they transition from liquid to solid form, but water expands, which causes ice to float on liquid water. This unique property ensures that aquatic life can survive underneath the ice layer in frigid conditions.