Dinosaurs are big lizards
Lizards are cold blooded and can’t self regulate body temp
Big critters produce more internal heat than small critters
Likelihood: in overall hotter world temps tropical regions were too hot for large cold blooded dinosaurs to fare well so the stayed in climate areas where they were more comfortable.
They probably regulated away all freon and substitutes for use in air conditioners which would have otherwise allowed them to operate in those environments
Dinosaurs aren't lizards. In any case, it is believed by many in the field today that some of them were likely warm blooded, particularly the carnivores.