How hot is it really with a hps?

I have a window for ventalation and it's working fine in this small room. It's well vented and stays around 75F.

How hot are the 400 Watt HPS/MH lights when running a small room like this, how much would I expect the temperature to be with one. I was considering a 250 watt HPS/MH and the thought crossed my mind about the 150 Watt because there's only a few plants. Anyone that can let me know about this I'll thank you now. It's the last thing I need to find out before I make the purchase.

Thanks...

400 will be fine i used to run them but now run 600w even with my door closed it would not get about 80f, if it did on a hot night id just open the door a little and have a small fan just at the door pushing fresh clean air in, took a small section out the roof and put up an extractor fan but i hardly use it, am using it right now but i run a 6oow and its a hot night but even now its 83f, and that pretty much fine.

The HPS don't get all that hot in my opinion but the MH get hot as fuck!

With an HPS I can get my plants to under 8"- 12" and they will not burn the tips but I need at least 18" on my Sunmaster MH.

HPS will raise my small area (3'6" x 4'6") by 8-10 degrees
MH will raise the area 15-18 degrees.

That's awesome because I was always under the assumption they got hot as hell. I don't want or need the carbon filter so I figured I would just keep the fan flowing with the fresh air. The fresh air perfect and I've had no problems with any discoloration this time for the first time. Everyone including the males were nice and green.