Yes. For hot pipes, it is recommended that the heating cables should not be installed on pipes heated above 155 F.
You should use the Heat Cable Kit
on both your hot and cold water pipes if the pipes are exposed to the cold outside air. So, if your pipes are under the house, in an exposed crawl space, or against an exterior uninsulated wall; then it might be a good idea to use the Heat Cables on both hot and cold pipes.
Remember, the water in the hot water line turns cold unless it is being used constantly.