Yaris overheating with A/C on

[instantninja]

I was out picking up some groceries today and being a warm sunny day I had the A/C on. on my way home the red coolant hot light started to flash, so I turned the A/C off and it went away. the ambiant air temps were 23*c, not what I would call hot, or what I would think would cause it to run warm.
I haven't had a chance to have a look at the condenser to see what kind of shape the fins are in. I did end up in the ditch in January and ended up with a bunch of snow packed around the engine.
when I have a chnce to have a look I'll get back to report what I find.