And yeah, I wish it was a thing here too
But actually, they are! (assuming you live in the US) If you go to a Japanese supermarket like Mitsuwa Marketplace they do sell heated canned tea there. Its quite good ~
Oh hi, I see you live in these burbs as well. Or Hawaii. Or Cali, Jersey, or Texas. But maybe here. You can also buy the cans of tea there (or on Amazon), and heat them up yourself with hot water. It's pretty nice on a cold day, but a lot of work to heat it up yourself