600watt hps how close smells toasty

i got this light chart off the net and it says with a 600 watt hps you can have the buds as close as 8 in. but it smells a little toasty! does that mean there too close?? please help before i fuck myself....

they'll start to brown if they're too close. I would start farther, give them time to respond, and then slowly move them in.

if the uppermost leaves are getting crisp, the room may just be too hot.

You may need to have a fan blow air between the light and the canopy, that will keep the heat from building up around the top of the canopy