Assuming that both male and female are of the same size and weight with no distinct difference in muscle mass…
Hmmmm…anecdotal data would seem to indicate “yes.” It is never the female that strips down at a midwinter football game. 
Well, men are ‘allowed’ more calories per pound when calculating diets. Since most calories end up as heat in the end, I’d guess so.
Men are allowed more calories per pound mostly because men have more muscle per pound, and muscles burn more calories than fat. But the OP asks about a man with no significant difference in muscle mass per pound so that reasoning is completely wrong.
Aside from likelihood, is that even possible? Same size, weight, and muscle mass?
Sure it’s possible. There are plenty of female bodybuilders with more muscle mass than I have and I’m a fairly average man. Of course I don’t know of too any that are my height, but there are plenty of female bodybuilders in the 5’8” range and plenty of men in the same height range with a lot less muscle mass.
http://www.straightdope.com/columns/020607.html
This may help a bit. Same muscle mass would produce the same amount of body heat, but supposedly a greater surface area in women would remove more body heat than men. This may mean that women would produce more body heat, making the same as men plus a bit extra to make up for heat lost. I’m probably way out but it makes sense in my mind.
The reason I asked about people of essentially the same size, is that I am trying to figure out if all men are human furnaces or just the one that I end up with, who are all bigger than I am, and therefor not a fair comparison.
Please note: Sharing a full bed with a guy who is 6’8" is a guaranteed way to make sure that you will never be cold again. Thank Og that he rarely spends the night
However calories are used (if they are used: as opposed to passing straight though!) they will end up as heat or fat. So for two people, one eating more than the other, neither gaining any weight, the one who eats more than other will have to generate more heat.
IMO it’s not a size issue, it’s a muscle isue. A normal man and woman of exactly the same height and weight would have very different muscle mass. Unless you are a female bodybuilder or you are in the habit of dating exremely skinny men then all men will seem like human furnaces to you simply because they have so much more muscle.
How does that go towards answering the question in any way? Do you have a reference that shows that men always eat more than women with the same muscle mass?
98.6 degrees folks. 98.6 degrees.
The OP said the man/woman were the same size.
The difference in calories is due to men being, generally, larger than women.
This is, of course, on average. chestnutmare 's, no doubt, studly uberman may personally turn out heat by the butt-load.
But on average, no.
Hey, this might explain chestnutmare’s statement “Thank Og that he rarely spends the night.” Now if he would just stop with the dutch ovens…
ba dum bump <ching> 
to expound on that, why does my lovely uberman ( 6’ 5", 250 lbs) always end up with the covers ?? it’ s not like he needs them !!
Men have, on the average, higher muscle tone than women. Muscle tone is caused by rapid, low intensity muscle contractions. It uses energy, and creates heat.
Women are also better insulated than men, and therefore give off less heat.
Tris
If they’re better insulated, why are they always complaining about being too cold?
Sandy 98.6 is core temperature. The OP asked whether men produce more heat, which is another beast altogether.
You are quite correct that on average all humans have a core temperature of around 98.6 (women’s is a little lower), however ‘heat production’ as chestnutmare is clearly using it has nothing whatsoever to do with core temp. Heat production in this context refers to skin temperature and skin temperature in turn is dependant on the amount of heat the body can afford to, or even needs to, waste by shunting it away from the core.
That puts us right back where we started. A knowledge that both sexes have the same approximate core temp does not allow us to conclude that men don’t produce more heat. Men could be producing a lot more heat despite having precisely the same core temp.
Nice try though.
PS, the difference in calories is not due to men being, generally, larger than women. As several of us have already said (including a linked staff report) the difference is due to the relative amount of muscle. In comparisons of men and a women of exactly the same size men still have higher caloric intake.
I’ve heard a theory (years ago - sorry no cite) that men will more readilly shunt heat (blood) to the extremities then women. THis would lead to woman’s limbs feeling colder (becaseu they are) though the core temp would be the same.
The extention of this theory goes on to state that this might have been a hunter trait. The men having to use tools to survive could sacrifice some core heat to be able to survive. In women it was more benificial to conserve heat to protect her reproductive system (and maybe the baby if one was there).