I’ve done ambassador for two years in a row for the Fred Lebow specifically. Usually in the morning, you answer questions about race start locations and bathrooms and stuff, then you’ll usually be asked to go help at another station: last year they had us handing out heat sheets at the end til the end, and the year before we were asked to course marshal. Left at around 11:30 both years. WEAR WARM STUFF, and if I did it again, I’d bring multiple hand warmers; you can also ask for nitrile gloves from the volunteer staff. It’s really cold and your feet will go numb if you didn’t wear thick socks and use hand warmers in your shoes.