More like sweating IN buckets, since that's what they call their head gear, and yes, they are extremely hot. Most times, they will rotate who is on 'stage' in a public setting so that they can cool off with their buckets off before swapping out again. During Star Wars Half Marathon, most of them stayed out in the warm sun for hours as people ran by (and took pictures with them) - one noted that he sweated out 6 pounds of water during that event.