Thermosphere temperature paradox?

[Molloy]

This quote from Wikipedia says that temperatures in the Thermosphere can reach 2,500 C during the daytime but "despite the high temperature, an observer or object will experience cold temperatures".

"The highly diluted gas in this layer can reach 2,500 °C (4,530 °F) during the day. Despite the high temperature, an observer or object will experience cold temperatures in the thermosphere, because the extremely low density of gas (practically a hard vacuum) is insufficient for the molecules to conduct heat. "

How is it possible for the temperature to be 2,500 C but for the observer or object to feel cold?

If there is "insufficient density of gas", and it feels cold, doesn't that mean it's actually just cold?

Thanks.

 

[Dale]

There are three basic mechanisms of heat transfer: conduction, convection, and radiation. In a very dilute but hot gas it is possible to have very little heat transfer by conduction or convection. All of that small amount of heat transfer would of course be from the hot gas to the person, but the amount of heat would still be small.

But that still leaves radiation. If the person is in radiative contact with a cold object, such as deep space, then it is easily possible for the amount of heat lost through radiation to exceed the heat gained by convection and conduction. That would lead to the sensation of cold even in a very hot gas.

 

[Vanadium 50]

You need to understand the difference between temperature and heat. You can stick your hand in a 400 degree oven for a little while with no ill effect, but will be seriously injured if you dip it in a pot of boiling water at only 212 degrees. That's because the air in the oven has a higher temperature, but less heat.

The upper atmosphere is an extreme example of this: you have a very high temperature, but carrying very little heat. So little heat that it's insufficient to replace the heat that your body is radiating away.