Heat Tolerance of Yogurt Cultures

I have an odd question…

How sensitive are the various yogurt cultures to heat? For example, if I dump a few tablespoons of fresh yogurt into a steaming bowl of oatmeal, is that going to kill off most of the cultures and render inactive the primary benefits?

Most bacteria dies at about 140 degrees if I remember correctly, so… yes I think hot oatmeal is hot enough to start killing it.