One summer in college, I worked for a steel mill, where hot and cold temperatures were needed to create our product. In the center of one of our mills was a massive 70-year-old cast iron heater named Davy. I don’t remember what temperatures this coal-burning monstrocity reached, but when those iron doors were open, you didn’t need to heat the factory. The furnace would open; stand back! My job was to shovel coal into the furnace, which was used to melt metal. Its glow was illuminated on workers’ faces whenever it was open. According to the full-timers, the building was rarely heated in the winter, except for a small heating and cooling system in the office. So, they stayed warm by working close to it – but not too close, because even on a cold day, it was still too hot to work near for long. The high-ceiling factory depended on the blazing heat generated by Davy, which was a beast on those hot summer days I worked there. Even at full speed, the overhead shop fans, which ran year-round, were practically useless. So were the few oscillating fans nearby. With windows only at the very top of our building, the best chance for air circulation came from the overhead garage doors, but on a sticky, stifling summer day, the best chance at relief was when a supervisor switched the shift start to four o’clock in the morning – which happened a lot. More heat was generated by the huge vehicles that carried the molten metal out, presumably to somewhere much cooler.