Sounds like you're trying to determine which gage to buy...
IMO, both factors are equally important. If you lose the pressure, you'll certainly overheat - Big time. If you over heat to a dangerous level, you won't need to know your pressure. If my guess on the reason for your query is correct - go temp. You already have a perfectly functional idiot light for pressure, so you're sort of covered on that end. Although I'm sure there are at least 50 more opinions for this question with only two possible answers. Oh, I use no gages. Good luck in your quest...
