It was so bad that drivers preferred the punishment uhauls handed out (there were more drivers than trucks, so those on management's shitlist got uhaul trucks) because they could actually stay warm.

I worked as a driver helper for the Christmas season of 2014, so I can give context. The trucks do have heat and A/C...technically. But the trucks are not at all insulated so they're freezing in the winter and the severely bare bones A/C can't keep up.