Years ago Under Armour used to make "Heat Gear" shirts with long sleeves. I cannot see that on their web site anymore. It was very thin and light with full arm coverage That would have been one way to help those arms.
But one other thing: the Aloe Vera plant that you may purchase at the local Home Depot's gardening center. You can buy a plant, grow it and use those leaves to give you that natural gel to smear onto your arms after a ride.
I don't know where you live and if that kind of plan will survive cold and harsh winters. But here in Southern California, those plants are common, even in the shopping center near me. I mean out in the open.
Oh, I went back to the Under Armour site and found it under "compression wear"
https://www.underarmour.com/en-us/me...pid1257471-100