In my pants.

So far the hottest planet discovered is HD 149026b @ 3,700 °F. The core temperature of the sun is 28,800,000 °F

I was actually just watching "The Universe" on the History channel tonight, and they had done a computer model (using 128,000 processors at 60,000 processing hours) to find out what actually occurs in a supernova. What they found was that when a supernova occurs, it takes about 3 seconds for the explosion to propagate across the star and in that time temperatures reach above 3,000,000,000 degrees Fahrenheit. That's 3 billion degrees. I'd imagine that's probably the hottest thing that we've seen, since they happen in our galaxy about twice every century and about once every second in the universe.

Happy Hour at the Big Bang Burger Bar, It's just a guess

well I know that it is not the UK - not until the expected heatwave that's due to arrive in 2080. Erm, now according to the hype in the UK, this must be somewhere that has the object of planetary doom in it - somewhere with a patio heater then, it must be.

Trying to determine the highest temperature (or "absolute hot") in the universe has been quite puzzling and even contradictory. On the other hand, discovering the coldest places in the cosmos has been more-or-less straightforward. For example, the areas in interstellar and intergalactic space hover around -454°F (-270°C or 3K). The Boomerang Nebula is the coldest naturally occurring environment that we know of with a temperature of -458°F (-272° or 1K) due to the rapidly expanding molecules coming from the poles of a Red Giant star. Scientists have achieved lower temperatures in a lab. It is likely that the radiant temperature of some of the largest supermassive black holes are much lower than what has ever been achieved in a lab since these objects radiate very little radiation (Hawking Radiation). Finally, absolute zero is the coldest temperature at -459.67°F (-273.15°C or 0K). But where and what object(s) could be the hottest place(s) in our universe? The first instance of the Big Bang was the all-time record high of our universe at a temperature of 10^32 Kelvin (1 followed by 32 zeros). If there happens to be a "wall" of plasma on the farthest reaches of our universe, it is possible that this "wall" of plasma might still have this super-ultra-hot temperature. I recently watched a documentary on NOVA about the String Theory. If the String Theory is correct, then everything in the universe is composed of tiny vibrating strings. If an atom were scaled up to the size of our Solar System (including Pluto), then one of these "strings" would be about the size of a car. According to the theory, these "strings" have a temperature of 10^30 Kelvin. When we think of heat, we associate it with how "hot" something is such as being in a desert or boiling water in a tea kettle. Actually, heat is the measure of how fast the molecules are moving--the faster they move and collide with each other, the higher the temperature. Another important aspect of heat is the density of a medium. The denser the molecules are packed together, the more you will feel the temperature. Think about how a 105°F (40°C) jacuzzi feels compared to air at the same temperature-the water has a much higher specific heat capacity and, thus, the heat feels much more intense than in air. The reason being is that there are places in our universe that have outrageously high temperatures but really don't mean that much. For example, cosmic rays are atomic nuclei moving through space at nearly the speed of light. As a matter of fact, we are being struck by a few of these that make it through our atmosphere every minute. If you take the molecular motion into account, these particles have extremely high temperatures of 10^15 Kelvin or higher. Ultra High Energy Cosmic Rays have temperatures of over 10^20 Kelvin. The reason you don't feel this heat is because there are simply not enough molecules to heat you up. The same situation would apply if you were in the magnetic fields of the jovian planets where the molecules are moving at speeds to produce temperatures around 1 billion degrees or even the Large Hadrian Collider with particles moving at a temperature of 10^17 Kelvin. However, there are places in our cosmos that are very hot and would literally vaporize anything tangible. After several years of studying Astronomy, I have also wondered what object would produce the highest temperature in our universe, especially a meaningful type of heat. Here is what I would say based on what I have read and what scientists know: For titanic events having a short duration: Gamma Ray Bursts There are several objects that could cause a gamma ray burst. The short-lasting bursts are likely the result of the collision of two neutron stars which produce a temperature of about 600 billion degrees Fahrenheit (350 billion degrees Celsius/K). The longer-lasting bursts results from a formation of a black hole when a hypergiant star collapses. Just after the black hole forms, it draws in matter from the star's interior and the bipolar jets collide and penetrate through the star’s layers emitting intense gamma radiation with temperatures in the several hundred billions of degrees. I read an article from NASA stating that a flare from our galactic core was the result of our supermassive black hole swallowing a star. It produced a temperature of over 1 trillion degrees Fahrenheit (600 billion degrees Celsius/K). A few months ago, I was watching a show called "Universe" which airs on the History channel. This particular episode was titled, "alien galaxies" and one of the professors explained that anything that emits intense gamma rays has temperatures well up in the billions or even trillions of degrees! Supernova The core of a supergiant star on its last day before going supernova reaches about 5 billion degrees Fahrenheit (3 billion degrees Celsius/K). During the supernova event, the core has a temperature ranging from 10 billion degrees to 100 billion degrees. For objects that have a continuous duration: Singularity (core) of a Black Hole: We have no idea what exactly exists below the event horizon in the center of a black hole. If it’s not exactly a singularity with no dimension, it is likely that a ball of ultra-dense matter resides in the core of a black hole and probably has some amazingly high temperatures. Cores of neutron stars and massive blue supergiants/hypergiants: The core temperature of both highly compacted neutron stars and some of the most massive stars have a temperature of about 1 billion degrees. Inner regions of a black hole's accretion disk: These places have temperatures ranging from several millions to several billions of degrees. In fact, Quasars are supermassive black holes that are feeding off of an abundance of matter. According to the "Absolute Hot" article from NOVA, quasars may be one of the hottest objects with temperatures of 10^14 Kelvin (100 trillion degrees)! After all, black holes are much better at converting matter into energy than any star. (Check out this article: http://www.pbs.org/wgbh/nova/zero/hot.html) Some other hot objects would include the surface of neutron stars which have a temperature of over 1,000,000°F (600,000°C/K). Actually, some of the stars with the highest surface temperatures are small white dwarfs. The one in the Red Spider nebula has a surface temperature of 900,000°F (500,000°C/K) while the one in the Red Rectangle is 450,000°F (250,000°C/K). In the end, I would make the guesstimate to say that the highest temperatures in our universe today would take place in the cores of black holes. After all, the highest temperatures occur where gravity is extremely high (i.e. neutron stars, white dwarfs, black holes). Near the center of black holes, the pull of gravity outpaces the speed of light and compress matter into unimaginable densities probably creating some kind of exotic matter. In such an environment I couldn’t imagine the outrageously high temperatures that would result. Until scientists come up with theories better explaining the anatomy of a black hole, I wouldn’t be surprised if that matter has a temperature in the range from 10^teens Kelvin to 10^20s Kelvin or even higher.

A desert.

One of my parties?

The hottest place in the universe has not been discovered yet and maybe it will never bee discovered but I think for now the hottest place may be at the center of the sun where there is abou 15 milion degree celsius. So the core of the sun is the most hottest in our galaxy

large hadron collider is one of the hottest places in the universe with temperature of about 10 million billion c.