I have a 1998 Airstream Land Yacht. I just moved to Hemet, CA where it gets 110° in the summertime. All faucets in the rig are scalding hot - hot and cold. Is there any way to keep the cold water cold?
Assuming that the water is not coming out of the spigot hot, fill your onboard water tank at night and use water from it during the day. That should, at least, help. Using a white water hose also helps as it absorbs less heat, and running it under the trailer as much as possible to shade it can also help.
And, welcome to RVF, @Marvyn, we're glad to have you join us. Lots of friendly, knowledgeable people on this forum.