Looking for a Space Heater.

It's May and time for the annual space heater hunt. Why am I looking for a space heater in May, you ask? Well, it's like this: they turn the heat off in my mom's apartment building the first weekend in May and almost without fail, we get a stretch of damp, chilly weather the following week. It's an older building with single pane glass so the area in front of her sliding glass door can get a bit chilly, at least for her. Now, it's happened before and you'd think she'd plan ahead and get one sooner. But no, that would make way too much sense, so now I'm stuck trying to find a heater somewhere. Needle in a haystack time. I think the local K-mart might have some or possibly the local hardware store. I've already tried Home Depot but it's all a/c and fans. Oh well, I'll find something I suppose. I guess, kinda, sorta, maybe, yeah, I don't know.