My job.

So recently I was asked to start doing truck days at work. I’m currently a CEM (customer experience manager) there. I said I would do it if it meant I would get more hours. I was never given more hours but they still put me on the truck. Truck day is when our company gets all the items we are out of or running low on. We don’t have a dock or any kind of machine to help with the truck, it’s just me and two guys unloading everything one box at a time, separating, and putting away a whole trailer worth of product. I only agreed to this because I was told I’d get more hours. It has been below freezing lately and we are outside from 3 a.m. til whenever we finish which is normally around 6 or 7. Today it was 22 degrees and kept dropping, we literally watched a puddle of water freeze today. I talked to my supervisor about how i can’t afford to get sick, especially because I’m not getting enough hours to pay for medical expenses. She basically told me to take vitamins and they’ll help me(they are expensive af too) especially since I’m barely making enough to cover bills. My point is I shouldn’t be forced to do something if they can’t hold up their end of the bargain. What do I tell my supervisor? I’m always the one who goes above and beyond for my job but this just doesn’t seem fair. I don’t want to sound like a shitty employee by saying “take me off the truck”, but technically this isn’t even part of my job description. 🙄