I'd pledge a few bucks!

Imagine that cop who last gave you a ticket, jumping half-naked into freezing water! Could there be more fun than that?

Sometimes they take the plunge dressed in little girlie costumes.

There are lots of polar bear clubs, whose members take a dip in icy water on January 1st or some other winter 's day.

Gaining less attention, but more purposeful, are the Law Enforcement Torch Run Polar Plunge® to benefit Special Olympics. The dollar amounts raised are impressive. It's city cops, highway troopers, and sheriff deputies all freezing their nuggies off for a good cause. In Illinois alone, 3,925 plungers have raised nearly $1.2 million for Special Olympics in seven years.

Here is the link for the Illinois sites.
Here is the link for the Missouri site.
Law Enforcement Torch Run Polar Plunge -- Google Search Results