this doesn't sound very accurate to me... i almost always keep my feet under the covers. even when it's super hot and the rest of me is lying exposed, my feet are usually still under the sheet.
Depends on the temperature... Feet are temperature regulators. Always have a blanket on though, summer and winter, my back can't handle drafts. Feet ain't worth nuthin' if I can't walk in the morning because my back is wiped out.