The Last Time We Went Fishing,

I mention it was really hot,

but what is the hottest it can get? firstly it is pretty much accepted that Absolute zero, that's zero degrees Kelvin, or -459.67 degrees Fahrenheit is understood by textbook definition to be the absolute coldest anything can be, a temperature threshold at which atoms actually lose all of their kinetic energy and stop moving completely (or at which entropy reaches its lowest value), there can be nothing stiller than completely still, and hence absolute zero is as low-energy as something can go, so to the other extreme how hot can it get? 

the short answer is 141,679,000,000,000,000,000,000,000,000,000 Kelvin, give or take a few zeros, the most straightforward candidate for an upper limit is the Planck Temperature, or 142 nonillion (1.42 x 1032) Kelvin (K)—the highest temperature allowable under the Standard Model of particle physics, but temperature comes about only when particles interact and achieve thermal equilibrium, this from Stephon Alexander, a physicist at Dartmouth University, “We just don’t know whether we can take energy all the way up to infinity, but it’s theoretically plausible, to have a notion of temperature, you need to have a notion of interaction", back to our days fishing, it was hot that day.