Nah should be fine... Cards are made to operate at those temps and have a built-in security that shuts the card down if it gets in the danger zone. Lower temps are always better though 
Think danger zone is above 120-130 C
Think danger zone is above 120-130 C
I disagree with this advice.
Check this thread for additional opinions:
http://forum.bitcoin.org/index.php?topic=18229.0
My 5830s are running ~60* C (open case with a household fan moving air through the case 24x7.