Re: Airlocks are for losers
I'm not sure that the cooling problem is a short-term enough problem to concern someone pushed out an air lock.
The power emitted by radiation, L, is
L = (Area) * (Stefan-Boltzmann constant) * (T^4)
where T is the temperture in Kelvin.
Choosing a 70-inch tall, 200 pound person, and the Body Surface Area formula from here, I get 1.65 square meters for area. The S-B constant is 5.67e-8 Watts/m^2/K^4, and T = 37 C = 310 K, so L is 864 Watts for that person.
The emissivity of the body matters there; strictly speaking that simple relation assumes an emissivity of 1. I think that's OK for a butt-nekkid solid at blackbody at 310 K, but I don't know that for certain, and certainly simple suits (like the reflective metal-foil types) would drop that power output substantially.
Adding more specs (male, 35 years old) to our subject person, and taking the metabolic rate formula from Wikipedia (the Mifflin-St Jeor Equation), I get a basal metabolic rate of 752 Watts for that body.
Looks like lots depends on what you assume for your suit, but with the heat capacity of water being about 4000 J/kg/degree, my guess is that thermal problems aren't going to kill you as fast as other things.