is my yeast dead?

So i harvested the yeast from my latest 2 batches of beer (wyeast london ale III and bavarian larger yeast). I sterilized some water but didn't have time to do the wash.
I kept the yeast/trub in the fridge and kept half of the water in a sealed sterilized jar on the side and the other half in a jar in the fridge.
I took the London ale yeast out the fridge to wash it with the refrigerated water but picked up the wrong jar and added the room temp water to the cold yeast..... I'm now worried that the sudden temperature change will have killed the yeast.... am I correct in thinking this?

I would make a starter, and see how active the yeast is. You will only be out a little DME. It would be really hard checking it now without the help of microscope.

Ok so I tried this with a little of the yeast and it seemed to produce gas (the cling wrap on the top of the jar inflated a little and and there was more yeast on the bottom of the jar than what I originally put in, I could also see craters in the yeast on the bottom (presumably where the yeast was giving off CO2) so I think I got away with it... thanks for your help.

So I made two beers on Sunday, a brown ale and a nice dark hoppy lager. I made a starter and used the harvested and washed yeast from my last two batches, I'm pleased to say they are now bubbling away very nicely so it looks like I managed to keep it alive and kicking! I'm one very happy guy.
I now feel confident that I am able to wash and store my yeast correctly.

So thanks for your input

Your welcome