I've wondered about those plastic Rival Hot Pots. I have seen a few in thrift stores and I have two of them. One is all white plastic and I think they came in other colors like purple, blue, black, green. I also have an older one that has a green metal bottom and sticker on the side with ivy leaves.
I am guessing these are meant to be a sort of kettle like the Regal Poly Perk or some of these metal coffee pot like ones I've seen in thrift stores also.
But the way the lid opens makes me think maybe they can be used to heat food as well? I just can't imagine cooking in a plastic utensil, it would seem it would stain or transfer taste to the plastic. But the bottom plate appears to be non-stick.
I think Rival doesn't sell these anymore, but Proctor Silex still makes a similar one that is blue and I have seen them at Walgreen's and dollar stores.
Oh Yes, they are meant to cook small amounts like a can of soup or something. I've got one laying around here somewhere but it's all metal like a little percolator but I'm having a brain freeze what make it is.