The Earth's thermosphere reaches 4,500°F, yet you would freeze to death if you were there.

The thermosphere is the second-highest layer of Earth's atmosphere, extending from about 56 miles to 375 miles above the planet. Temperatures here can soar to 4,500°F (2,500°C) due to the absorption of high-energy X-rays and UV radiation from the Sun. However, temperature is a measurement of the average kinetic energy of particles, not necessarily how 'hot' an environment feels to a human.In the thermosphere, the air density is so low that it is effectively a vacuum. A single molecule might travel for kilometers before colliding with another one. Because heat transfer via conduction requires physical contact between molecules, there are simply not enough particles hitting your skin to transfer their thermal energy to you.According to NASA, the primary way an object loses heat in this environment is through thermal radiation. Without a dense atmosphere to provide insulation or conductive heating, your body would emit infrared radiation into the cold void of space. This loss of energy would cause your body temperature to plummet rapidly despite the high-speed molecules surrounding you.This phenomenon highlights the difference between temperature and heat. While the temperature is high because the few molecules present are moving at incredible speeds, the total heat content is extremely low. This is why satellites and the International Space Station require specialized thermal control systems to manage extreme temperature fluctuations in this layer.