[TheSpiceIsLife]

This has got me interested now.

At the equator, on the surface of Earth, solar radiation is about 1kW per square meter. According to this¹ wikipedia article 55-60% of solar energy is lost on its way through the atmosphere.

So would ~2kW / square meter at thermosphere height be enough to make you feel warm-hot despite the heat lost to evaporative cooling from sweating?

1. https://en.wikipedia.org/wiki/Space-based_solar_power

Edit: correct highest to height

[mncharity]

One might sweat a couple of liters/hr, and thus might manage 2 kW. But that's not needed. Between bright hot Sun, too hot, and dark cold deep-space sky, too cold, Earth spins, mixing too hot, and too cold, into not too bad. And so can you - the "barbeque roll" thermal management strategy for satellites. And if you're head-on to the Sun, or in shadow (holding an umbrella)... I don't recall whether radiative loss is sufficient to shed basal metabolic rate without sweating or not. If not, you might build yourself some elephant ears, and sleep with them edge-on to the Sun (and Earth). But EVA suits use water sublimation cooling - because people do EVA to strenuously exercise, even in the bright sun.

Science education content, down to kindergarten, mentions Sun heating Earth. But pervasively fails to mention deep-space sky cooling Earth. So a lot of explanatory leverage is left on the table - "Why are nights cold? Especially with clear sky? Especially in the desert? Why are mountains snow-capped? Why is winter colder?" etc. I wish I knew of a forum/community in which to discuss and create such improved content, but I've been failing to find one. :(

[jacobush]

But how much can you irradiate to the black space?

[Teev6Hul]

Sweating would be a lot more effective in a near-vacuum, if we assume you'd wear one of those futuristic mechanical counterpressure space suite.

[k__]

How come? I thought sweating worked by helping to lead the heat to the air

[jacobush]

No, it works by using up heat to change a materials' phase, that is turning it from liquid to gaseous.

[zamalek]

... and phase-change is exactly how your freezer works.

[wildmusings]

Either way, you'd be killed by vacuum exposure.

[jacobush]

Indeed, unless you'd have that fancy space suit which is semipermeable.

https://en.wikipedia.org/wiki/Space_activity_suit