How long would an astronaut in space in his PJs last 'ere he rot?

Well, there’s still radiative heat transfer. And one could consider the “temperature of space” to be the temperature at which an object in space would come into equilibrium. By that measure, space in the vicinity of the Earth would be at about the same temperature as the Earth, since after all, Earth itself is a body in space (more or less) at temperature equilibrium.

Wouldn’t the moon be a better example, having no atmosphere?