I found this on uncoached.com:
“On September 12th, the students at the University of Florida decided to take off all (well, most) of their clothes and run across campus in nothing but their underwear. How I would have missed this is beyond me. Perhaps it’s because whenever I look for “Undie Runs” I type in the term “Undie Run” when searching and not Underwear Dash. Stupid me.”
Apparently this is an annual event in aid of charity. Makes the student rag weeks we have in the UK look a bit tame, but then with our weather it would be a brave person who stripped to their underwear in September and ran through the streets.