What is the hottest temperature ever recorded in the universe?

Answer 1

4 trillion degrees Celsius during gold ion collision experiments.

Answer 2

That depends a lot on what you want to include in the term "space". The interior of stars can reach a temperature of a billion kelvin, or even several billion kelvin, in the case of supernovae or hypernovae. If you don't want to include the interior of stars, the hottest temperature would probably be close to stars. Our Sun's corona has a temperature of about a million Kelvin, which, strangely enough, is about 20 times as hot as the Sun's surface.

Answer 3

Temperature is synonamous with molecular motion. Rapid motion, higher temperature. Slower, lower temperature. Since the universe is very largely vacuum, i.e., empty space, there are no molecules (material) running around and therefore temperature is not defined, i.e., it doesn't have a temperature!

So what happens if you get yourself into outer space all of a sudden? Do you have a temperature? Yes - what it was before you hopped into outer space. Shortly thereafter, your body disintegrates, and all its molecular components separate and spread. The heat energy is totally dissipated. So does this mean it is cold out there? No, because there is nothing there except your remnants which are indeed very cold.