I'm a grad student and a lecturer of a section of a first year undergrad math course. This is my third year involved in teaching and this is first time something like this happened.
Last week, a student sitting in the front row fell asleep during my teaching. He breathed very heavily and was very distracting. I wasn't sure how to act and I didn't want to embarrass/scold him in front of everyone. Some other students noticed it, and I quietly, without others hearing it, asked a student behind to push him. He woke up and we continued like nothing happened.
Today it happened again and I got stressed and lost the flow of the argument during my teaching and got angry. But I kept my composure and "accidentally" touched him with the paper sheets as I passed by and he woke up.
I haven't talked with him about it, and I might ask a course chair for advice. But I feel very disrespected. Only tangentially related, but I'm not that boring, I get 90% very good anonymous feedback/review at the end of every semester.
After the class I mentioned it to two of his friends/classmates, as they also noticed it, and one of them giggled and said that he will tell him to sit in the back next time (this is not what I want though).
What is a good course of action? This is the US, and I'm a foreigner and if I act the way it is normal in my country, here it might be considered overly inappropriate and I don't want unnecessary tension.
UPD: I like cag51 answer and will follow it in practice. Thank you all, but honestly, some of your reactions were hostile. I come from another culture and a notion of respect is very culture-dependent and don't always have a pragmatic rationale. And one of my problems was that it disturbed the lecture flow which affects subsequently other students experience. I came with a good will.
I don't assume any disrespect anymore, but the noise may still be disturbing so I will talk to him as gentle as possible about the noise. Also I will suggest him, in the case of personal troubles causing it, the help options provided by school.
UPD2: Please don't respond explaining why sleeping is respectful or disrespectful. Respect is a social construct which depends on the culture but it seems you're assuming your culture to be universal. Since I live in the western world, I don't have a problem of following western social constructs.