without more information, such as what else you are seeing as symptoms and so forth. Is it hard to start again or does it start right back up? Does the tach do anything odd? Does your traction control go off?

The temperature thing (dies when its hot) would lead me to believe it is an electronic failure of some kind, i.e. sensor, but that doesnt narrow it down much either. My first thought is the Crankshaft Position Sensor, but the MAF can produce some of these symptoms as well.