Anyone ever been shocked by their heated seats? (And no, I don't mean shocked by how nice they feel on a cold day or how hot they get...

)
Riding home yesterday with the seat heater on I began to notice what felt like a slight, regular twitching sensation on my right leg. I then noticed the hair on my leg hair standing on end. As it increased in intensity and became more noticable, I turned off the seat heater and it all stopped. (Background - Yesterday was humid and rainy and I had gotten wet running to the car in the rain. Not soaked, nothing unreasonable, but a little wet.)
A little later, I flipped it back on and once again, it shocked me!

This time it was a faster bandwidth (maybe because the seat was now cold?) More like a regular shock that I felt in my leg and my lower back. I immediately turned it back off.
I would have never expected that the slight amount of rain on me would cause a conductivity issue with my seat heater circuitry. Nor have I have never experienced anything like this with any other heated seat. I tried it again this morning on the way to and from church and it didn't repeat. However, I'm now a little concerned about getting into the car and using the seat heaters anytime it's raining or snowing. Anyone ever experience this? How could a tech even safely diagnose an issue like this? (My wagon's still under warranty, BTW.)
Any advice/comments/experience GREATLY appreciated!
Mike