Right now, we have the aluminum cups in our motorhome (dropping rv gift ideas to others to complete the set one day). It is 90 degrees and next to me, as I type this, is my treasured purple metal cup. Though people who live in homes made of brick, sticks or straw (ok, 3 Little Pigs reference there) do go outside in the heat, no one does it more than rvers.
Our camper is great, but nothing draws us outside more than warm weather, after freezing to death all winter. We want to sit outside, under the awning, and have a cold adult beverage. Aluminum tumblers make it possible, keeping our drinks cold for a long, long time.
But the other reason a vintage aluminum tumbler makes a great rv gift is because it won't break! Yes, this is very important in the rving world as dishes and glasses bounce around down the highway.
So this lovely aluminum set will be a treasured gift for any camper dweller on a hot summer day - and because it can bounce around the cabinets while on the road, without getting as much as a scratch, it will be appreciated all year round!