Originally Posted by MikeMike
The wet shirt deal works far better in less humid, yet still hot, environments.
You'll need to soak it in ice water when riding in high humidity, and then the inevitable soggy waistline happens. And saggy too, if you are like me.
I've done the wet shirt in Alberta and the Baja, and it was very pleasant in both. I didn't think it would make any difference what temperature the water was that you dunk it in......it very quickly equilibrates to some combination of your body and ambient temperature. I would say just use any temperature you like.