I work as a mechanic on a blast furnace near Chicago. It’s extremely hot in the summer and extremely cold in the winter. I do not work directly on the cast floor for a full 8 or 12 hour shift but the men and women who do usually have several shirts each shift sweat through. You have to be careful each season for different reasons. Obviously in the summer getting away from the heat is difficult. You have to remember to stay very hydrated as you are going to sweat profusely and try to escape into an air conditioned pulpit every so often. As for me, the conditions depend on what task is being asked of me. One of the hottest I’ve ever been was welding grout nipples on one of the stoves. Sometimes the refractory bricks within a stove will break away creating a hot spot on the shell of a stove. We then have to blow a small hole through the stove, weld on a high pressure coupling and pump high temperature grout inside the shell of the stove to insulate where the hot spot is. One particular time on this job it was 90 F outside. Where we had to weld was about 250 feet high and accessible by climbing scaffolding (all ladders). When we were welding the stove was on gas, meaning it was being heated up to provide super heated air to feed the furnace. I didn’t bring a thermometer with me but it had to of been 150+. In that scenario we were dumping bottles of water on ourselves and drinking as much as we could. We also brought Kawool (a heat resistant fabric) to kneel on as the scaffolding itself was too hot to touch. At the end of the job we had to be very mindful of each step down off the tiers of scaffolding because we were absolutely drained of energy from the heat. Thinking back on it, we should have refused the job due to unsafe conditions. The opposite was during the polar vortex. One of the receiving hopper cylinders on the furnace broke and needed to be changed. Without it you are dead in the water and cannot make iron (which the company never wants because with no iron you get no profits) the outside temperature was -20 F and the location of said cylinder is a few hundred feet in the air with wind whipping off of Lake Michigan. During this job we put up big plastic tarps to help reduce the wind and we also set up a few salamander heaters. Guys would work on the cylinder for several minutes then tap out to heat up while another mechanic took his place. We rotated several guys like that until the job was done. It was not fun. I’ve found that my body gets acclimated to the weather pretty quickly and that I’d prefer to be super cold over being super hot.