Temperature Question Help

Hi, this is kind of a stupid question but when you read about ideal temps for cannabis are they talking about the ambient temp in the grow room or the temp of the area around the top of the plant closest to the light? Im using 400 watt MH right now and the room temp is perfect but the top of the plant can get in the upper 80's. I would really appreciate any feedback, Thanks.

Ambient room temp is the subject I believe, but you should be using some sort of cooling to keep temp by the lights as close as possible to room temp.
If you were growing outdoors, the temp at the canopy would be really close if not the same as soil level.