What's the hottest thing in the universe and how does it compare to other extreme temperatures found in space?

Well, darling, the hottest thing in the universe is the inside of a supermassive black hole, reaching temperatures hotter than a Kardashian scandal. Compared to other extreme temperatures in space, like those in neutron stars or supernovae explosions, the inside of a black hole is like a blazing inferno while the others are just spicy jalapeños. Next question, please!