In the heat, I drink mostly the same wine I always drink, but if I were in Dallas in July, it would be indoors with the AC on. But I am a little more likely to drink whites and roses, less likely to drink heavier reds like Barolo and Bordeaux, more likely to drink wines like Zinfandel that pair with grilled foods, and I would probably tend to serve wines cooler than I would have in cold weather.
But I’m never part of the “just drink beer” chorus, whether it’s food-wine pairing or weather discussions. I love wine, and I love it just as much in July as December.