2003 Mazda 6 engine is stalling when it reaches normal temp

I have a 2003 Mazda6 with a 6 cyclender engine. The car runs fine untill it reaches its normal operating temperture, so in the morning on the way to work I may drive 20 miles without a problom, but on the way home when the weather is warmer I may only get 4 or five miles and the car will either stall out, or it will be unresponsive to the gas pedal, and will simply idle between 1250 and 1500 rpm's pulsing between the two. Obviously the problom will arise even quicker if I am running the A/C as the car warms up faster. Once the car stalls out I can switch the ignition to the off position and restart it and the problom will go away temporarily, but I will have to continually be restarting the car all the way home, every couple of miles or so. Do you have any idea what may be causeing this, is it fuel related or electrical?