If you do not enjoy swimming in ice cold water, you may want to think about purchasing a solar cover for your pool. Solar swimming pool covers are designed to trap heat in the swimming pool during the time when it is hot during the day but still quite cold at night. Under the right conditions, cover like this can keep the pool several degrees warmer than it would be without covering.
For a relatively small amount of money, homeowners can get themselves one of these nifty accessories. In addition to helping to keep the pool warm, they also do a bang up job at keeping out falling debris like bird poop. Nobody wants to go swimming with that. These covers are not really very heavy, but they are easier to handle with multiple people, so if you do not have a helper around, you might want to consider getting an automatic version for your home. They are more expensive by make working solo much easier.