I was on my way home from a distant friend's house, about a 78-mile trip one-way. I was driving on average 80mph with very little traffic. I made it home okay, and the next morning, drove to work which was a 17-mile drive with a low-level amount of traffic. When I was about an exit away, my temperature gauge turns on: yellow. I decided since I'm so close to work, I'll note the issue for now. Upon leaving work about 8 hours later, I drove less than two exits from work, and the temperature gauge turned on but this time: red. I reduced my speed and made it to my destination (was very close, within 5 miles) and got a ride to an auto store where I purchased some coolant. I had to drive home after my 2-hour or so event, so turned on the heater after filling up the coolant reservoir. Made it home and next morning reservoir left a small leak on the cement floor. I noticed the reservoir was low again so filled it up and drove it to the dealership. I used up a whole container of coolant in less than 24 hours. Dealer diagnosed the issue as cracked heads and replaced the head gaskets and put a new cover on them, all covered under my extended warranty (thank GOD).