Yes, just as with green shoulders high heat causes uneven ripening. Not much you can do about it but provide some shade if possible.

Dave

I've got some extreme green shoulders on some of mine too. My best solution is to let them ripen as long as possible before eating. I picked some Rutgers with almost the whole top half still green while the bottom was red. I let them sit on the counter for a week after picking and they continued to redden, so by the time I ate them only the top 1/4 was green.

Re. what edweather said, I think I've read that picking them early (as soon as the color breaks) lessens the irregular-ripening problem.

Since tomatoes grow in Texas where I suspect it gets very hot, the couple of weeks of hot weather here shouldn't have impacted them. Now we have cool nights (48-50F) so I suppose getting them ripe will be almost impossible.