Job wants me to do something that is dangerous and not what i was hired to do need advice?

been at my job for about 5 years. i was hired to do data entry work for a company. the job got rid of 90 percent of the people who worked there and only kept a few people. i was taken out of my job but didnt complain when i had to leave an a/c office and sit down desk job to work in a hot warehouse environment standing all day plus they made me learn how to drive a forklift to on top of this stuff i was never hired on to do. i have never complained and stuck with it because i need the money but now the place is wanting to go into something that is so beyond the scope its nuts. they want all the employees who are left to learn how to weld or to build stuff with power tools. i am not a carpenter or welder and i feel if my job ends they should lay off. my background is office work which is why i orfginally took this place. i feel the work could be dangerous to since i m not a welder or carpeneter. i literally saw propane tanks and blow torches. that kind of work is not what i was hired to do and i think enough is enough. also to for this summer they have decided that the employees can not use fans in the warehouse. we have no air circulating in the place at all and it will get so hot in there i am afraid of passing out to. any advice on what i can do? if i refuse to do dangerous work will i get unemployment? i am not comfortable at all with welding or carpentry work i didnt take this job to do that stuff it was supposed to be data entry? any advice on what i can do here would be appreciated. thanks!