What percentage of your body heat allegedly escapes through your head? We can't remember, either, but we know it's enough that you should heed your mother's advice and slap on a cap when it's cold outside.

Ahhh, but what kind of lid sends the right message in see-and-be-seen Park City? After conducting a scientific study, we can conclusively report that the chapeux of Sundance break down something like this:

The Hat Squad: Every girl's crazy 'bout a sharp-dressed man... in a fedora. Giancarlo Esposito, Danny Houston, and Nick "Nice Shirt" Nolte chose style over comfort.

Knit Wits: What can we say? Watch-caps may be dorky, but they are warm. Note the toasty ears on Paul Giamatti, Terrence Howard, Sting, James Van Der Beek, D.B. Sweeney, and Jack Osbourne (more of a git than a wit), as well as our own Lisa Rosman.

Newsies: Who knew? Fans of the Christian Bale Disney flick were out in force. Note O.G. indie icon Dennis Hopper in a snapshot by Roger Ebert, as well as Julianne Nicholson in a scally, and Tim Hutton busting out a Greek fisherman variant.

Surprising no one, Bai Ling went her own way in a fuzzy fuschia beret.