I'm having a problem with my power steering.

Car:
91 EF DX, lowered 2"

Weather:
Snow and Ice everywhere, cold temp (-10 to -15)...


Symptoms:
Somtimes when I go to start my car after its been
sitting in the cold for a while, a soon as it fires up,
the power steering kicks it spinning the steering
wheel super fast ccw. I can't move the car cause
I can barley budge the wheel (well, I can but it
takes quite a bit of force). It's only happend twice
in the last week.The first time, got out poped the
hood looked around, got back in the car and the
steering was fine, the second time, I turend off the
car poped the hood sniffed around for this burning
smell, got back in and the steering was fine.

I dont think I'm low, cause there's no "dry steering"
niose, if you know what I mean..
Does power steering fluid freeze?

Any ideas?

Thanks.