Final answer:
Animals in cold environments lower the freezing point of water in their tissues by increasing solutes in their body fluids, such as salt.
Step-by-step explanation:
Some species of animals in cold environments lower the freezing point of water in their tissues by increasing solutes in their body fluids. This freezing point depression allows them to survive in freezing temperatures. Salt is one of the solutes that can be used to lower the freezing point of water.