How far from my 400w hps to put my plant?

Ok so i got 1 small plant in flowering and i got a new 400w hps to help it flower now here is that problem i i have done the check with your hand for heat thing to see when it burns but it only really burns my hand at nearly 6 inch from the bulb now this bulb is not cool tube and from what i read that would kill my plants if they were that close right? the temp in the room is about 75 deg steady. so what do you guys suggest?

1) What is the temperature at the canopy?

2) When in doubt,start 12"-18" above the canopy and lower 3"-6" a day until digns of light scorching.

The hand test thing....
If your had doesn't become uncomfortably hot at that distance...
That's how far to have it away from your canopy.

Ok just set it to 12 inches away and then if they don't burn at all ill go to 8 inches the next day. thx for the advice guys. Not sure why but everything i read about hps made me thing they trow all kinds of heat but mine hardly raise the temp in room at all with out vent and just small fan. Also the temp of the canopy is around 76 with out the fan with its same as the rest of the room 72-75.