Is there a highest possible temperature?
Its not known but the hottest temperature (absaloute hot) Is believed to be the Planck temperature which is 100 million million million million million degrees Celcius., or 10/32 Kelvin. A hotter temperature than the hottest can exist theoretically though. Infinite temperature is believed to be possible at the very centre point of the inside of a Black hole were all matter could be pushed into the size smaller than the head of a pin.