Dry yeast mixed with cold water

Hi,

I am a complete newbie to home brewing. This past weekend I finally bought a home brew kit and set out to brew a porter. In all of the excitement, I misread the directions on the yeast package. Instead of mixing the dry yeast in 38 degree Celsius water, I mixed it in 38 degree Fahrenheit. I didn't realize this until hours after pitching into my fermenter. Do I have anything to worry about?
I did have active bubbling in my airlock for about a day and a half but all activity has stopped. There are very tiny bubbles on top of the fermenting beer now.

I

You're fine, and it'll turn out fine. Most likely your beer already fermented out. Relax, everyone stresses over that first batch. In a couple days open the lid, and the surface looks pretty clear, take a gravity reading. (Sanitize a turkey baster to take the sample with). If its down where it should be (most likely under 1.020), wait another week, then bottle it.

A more technical answer is: dry brewer's yeast is best rehydrated in 90-110F water. When rehydrated around that temp, more of the 'frozen' cells come back to life. You probably killed off a good number of cells rehydrating at 38F. That's not a big deal for two reasons.

A. The yeast pack probably had like 220 Billion cells to start with (more than plenty)
B. Yeast reproduce quickly. In roughly 12hours, your yeast that survived reproduced enough cells to ferment the wort. They're worse than rabbits in that sense =)

If you saw active bubbling, you had fermentation, no need to stress