For today technology, it's as hard as flying an empty crew module with all the live keeping equipment turned on. Add Buster from Mythbuster to get more accurate data about the forces on a human.

I think SpaceX used a piece of cheese in one of their test fliying arround Earth, just to show that the temperature was never outside a confortable range. They could have user the sensor they already had, but using the cheese too is good for PR.