the astronaut in question is flash frozen, his blood freeze dried
instantly, assuming the astronaut in question didn't explode immediately
from the air pressure difference. This is not a really fun experiment.
Don't try this at home, kids.

The reason heat does not travel easily through a vaccuum is because heat
is kinetic energy, which operates at a much higher collective density
per cubic environment variable than in outer space. Consider the fact
that in outer space, the closest atoms are together is about a meter
apart, no accounting for dust and debris say in a ring like around
Saturn or an asteroid belt, whereas on Earth the atoms are much closer
together, say anywhere from a nanometer on up(that's 1/1,000,000 of one
meter). You can feel heat on earth because there are more atoms to
transmit heat than there are in space. Got it? Good. Since kinetic
energy is an active force, the less there is around it to support the
force exerted, the less force can be exerted and the more force must be
exerted to maintain equilibrium. It is a recursively dynamic equation
bearing on that which can be used efficiently for kinetic support
grounded to the base state of consumption rate needed to maintain the
ground state.

Is your question leading somewhere?

Shadowmega wrote:
I already posted a question about heat asking how heat travels through
a vacuum, but everybody assumed I was talking about starlight and I
therefore got a bunch of responses relating to photons and
electromagnetic waves. So allow me to rephrase...

If an astronaut removes his helmet in space, what happens to his body
heat considering heat does not travel through a vacuum?