This is more for the rookies out there. Temperatures will get cooler and colder as we go and the water wetter in your rads and engines will freezup. This can cause considerable damage to the small passages in your rads and even your engine.
You need to drain and refill the system with a proper coolant or make sure the bike (s) are in an area where it never freezes.
This is also a good time to get your tires off the ground, put fuel stabilized in your tank and take those wet smelly gloves out of you helmet.