I have 3 potted bushes that I left outside until the beginning of January.
When things finally started to get cold here (zone 6b) I brought them
inside. They started to come back quite nicely, then I realized that an
aphid outbreak was occurring. I dragged them back outside and sprayed them,
but I didn't get all of the aphids. I've sucked some of them off with a
dust buster.

It's supposed to go down below 30F over the next couple of nights. Do you
think I could kill the aphids by putting the plants outside for a couple of
hours in the cold temperature?

Thanks.