The wife says she saw steam/smoke on the outside of the '01 Camry (163K miles), while running the heat. She noted it was on the passenger side, and thought it may have come in through the fresh air/heater vent on the passenger side.
I looked under the hood, and saw no wet spots, indicative of a bad hose. The hose from the bottom of the power steering reservoir, where it feeds into a steel fluid line, was darker than the rest of that hose. Wiped my hand on that, but came up dry. Fluid levels are OK. The check engine light is not ON.
I have not been able to get it to happen again, but I have only been chasing this an hour. It has been 2 hours since she reported the issue. At that time, she had only driven the Camry 4 miles to pick up lunch. At that time. she was sitting in the drive-thru line on level ground.
Of course, I am unable to get it to happen again.....