Ok, an object in space will not have any conductive heat losses, but is subject to radiative heat loss, which for a human is about 700W * (1-IR albedo). In addition, it is subject to solar heating, which for a human will be about 600W * (1-visual albedo). It is nearly impossible to change the rate of radiative heat loss; the rate of heat absorption depends upon how much is exposed to the sun, so changing position (or having a dark side and a light side) will give some control. Most clothing and super-suits don't have an albedo above around 0.3, which means we can mostly not worry about albedo; figure on emitting 500W and absorbing 400W
A resting human produces about 100W, so with moderate lighting it should be possible to come fairly close to equilibrium. However, this can go out of equilibrium very easily: if you suddenly go up to a level of moderate exercise (600W, equivalent to about 500 Calories/hr) you're now producing 500W more than you can get rid of, which results in body temperature rising by a degree in 5-10 minutes. On the other hand, if you go into shade, either your body temperature starts to drop by a degree every 8-10 minutes, or you have to be active enough to make up for that 400W of sunlight that isn't coming in.
On the ground, none of this is a factor, because the atmosphere conducts heat away, keeping temperature under control. In space, it's a fairly significant problem, so yes, you want temperature control (both heat and cold).