No luck switching keys... I'm running out of ideas. Here's a shot in the dark though. My symptoms started appearing right after a trip to LA where I was driving/parking in 100-110 degree heat for 3 days straight. I'm normally in San Francisco where temps are always around 70. It seems like a lot of these posts have come up in the last month or two right after the heat waves across the country, anyone else have a similar experience?