Lighting, Light Fixtures, Ceiling and Exhaust Fans - Light fixtures and sprinkler heads

I am looking into adding some recessed lighting in my third floor hallway. Right now, it only has a single two-bulb ceiling fixture at the top of the stairs, so the other end of the hallway is always dark. I would like to replace the current fixture with a recessed can and add two more recessed fixtures down the hallway to provide more even lighting. However, being a 4-story townhouse, I have a sprinkler system and direct-wired smoke detectors. While at HD looking at light fixtures, the gentleman there stated that there may be a buildnig code requirement for spacing between a ceiling fixture and a sprinkler head to ensure that the heat from the bulb doesn't melt the element in the sprinkler head and set off the system. I have looked through the International Building Code (2003) and International Residential Code (2003) and haven't found any reference. I am going to try and look through the International Fire Protection Code tonight. If any one can point in the right direction or code book, I wuold appreciate it.

Thanks,
Neil

Try and identify the sprinkler head and look at the manufacture site. I think that spec would be on the head not in the code.