Brrr! When the weather is really cold, people put antifreeze in their cars to keep water in the engines from freezing. The antifreeze lowers the freezing point of water. This means that the water must be much colder than 0°C before it freezes—so the car keeps running.

Scientists have discovered that some fish that live in the polar regions actually have proteins in their blood that act as antifreeze. The antifreeze keeps their blood from freezing in their bodies.