If you have pasteurized milk that is steamed for lattes, could that end up making you sick? The steaming seems to occur at a high temperature.
No, there is nothing about raising otherwise-safe milk rapidly to a high temperature that is going to make you sick. Unless you are already lactose intolerant or otherwise allergic to milk. Raising milk rapidly to a temperature above the danger zone (140 F / 60 C) is going to make it safer, not less safe.
As a general rule, and assuming that there is no underlying medical condition, merely drinking heated milk will not make you sick. However, I have heard this assertion around the coffee shop from the Ethiopian ex-pats who frequent it.
Apparently; their tradition dictates that they eat something with their lattes, lest the milk make their stomachs blow up. When asked, one of them told me that the same did not apply to milk that had not been heated.
You can certainly heat almost anything, including milk, to the point where it tastes terrible. And you can heat some things to the point where they will make you sick, but milk isn't one of them.
I had two latte today on a fairly empty stomach at the coffee shop - now I usually have black coffee, but today I thought I'd have latte.
Afterwards and during, my belly swelled up, I could not STOP FARTING ! ...it was very very uncomfortable, I also got terrible stomach cramps.
Then around an hour later I feel very shaky and sick.
Can heated milk in latte make you ill, ABSOLUTELY !
...I have heard a rumour that you should eat something with a latte - but to be honest, my experience today with coffee and heated milk has put me off latte for LIFE !