Highest temperature ever

At the very instant of the Big Bang, 13.7 billion years ago, the universe is thought to have had infinite temperature, as it existed as a single, infinitely-small and infinitely-dense point. Just 10**-43 seconds later, known as the Planck time, the universe had cooled to roughly 10**32K, and expanded to a size of around 10**-33cm across.

The hottest temperature ever generated in the lab is 4 trillion Celsius – 250,000 times hotter than the Sun. This was achieved in experiments using the atomic collider at the Department of Energy's Brookhaven National Laboratory in New York, USA. Gold ions were smashed together to make explosions that lasted only for a few milliseconds.