In Canada most or all employees can refuse work if they legitimately and reasonable believe an aspect of their work is unsafe.

I've used it a couple of times over the years. The last time being the outside temperature was over 30, and the AC was broken, leading to my office being mid 20s. I felt sleepy, nauseated, and just plain too hot.

I refused to work until the AC was fixed. Although my employer and I worked out something, new AC was installed the next spring.