While driving in Phx I heard what sounded like a paper stuck in a fan sort of noise and noticed the temperature gauge climbing toward the 3/4 mark. I immediately switched on the heater fan to bleed off the excess heat and watched for an automotive repair shop nearby. After explaining this to Pepboys, a mechanic performed a diagnostic exam and explained that I had blown a head gasket. I paid for the diagnostic test, called my local mechanic and explained the problem then drove the 30+ miles to his garage. When I pulled up, he shouted to keep the engine running and immediately checked the engine.
The radiator hoses were flexible, the engine was not hot and the oil tested clear (no presence of coolant). He surmised that something had wedged in either the radiator fan or the air conditioner fan (always running) and was dislodged when I switched the heater fan onto high.
This is a 2003 vehicle with 55,000 miles and has never overheated. Pepboys seems to be in the business of making money off the vulnerable.