Do you spend a lot of money on heating water? Do you often have a lot of condensation on your cold water pipes? The solution to both of these issues is the same. You need to install pipe insulation. This is especially important if you have a lot of exposed pipes running through your home. Uninsulated pipes in basements or crawlspaces can quickly get cooled down in the winter or heated up in the summer. If you can access the pipes, then installing the insulation is not a complicated job.
You can find pipe insulation in most hardware stores, and it is usually sold in pre-cut lengths. Some of them come with glued edges that will seal up once you pull off the backing of the glue. To get a better fit, you might need to cut an angle for the corners and then tape those up to seal it as well as possible.