I need help saving a black widow!

A while back I noticed a small, oddly shaped web in a very high-traffic space in our office. One early morning I got the opportunity to see the spider who made that corner her home. To my surprise it was a black widow! Not thinking, I told my boss about her, but he has so far done nothing. Nevertheless, I'm still worried the spider is going to get gassed/crushed.

The problem here is she made her web under a non-movable shelf which is difficult to reach under, let alone see anything under there. The only way I can get her out of there is if she's on the outer-layer of her web (not under the shelf) where I can see her. This is rare, so I guess my first question is how do I coax a spider out of hiding?

My second question is how to take care of her? It's cold outside and don't want to risk putting her out there. Thank you very much!