You're getting 2 7970s inside a case to run at 1180 and you're complaining?

Be happy.  I have 2 of those same Gigabyte 7970s running at 1110/125 in an open rig running 85C/79C directly on the motherboard (ambient 80F-90F)

Open your case up and maybe put the miner in the garage if you have one, or build a cover and let it mine outside.

Unless you add a lot more core voltage you're not going above 1180 on most 7970s.