Crossfire Question - Temps

[Ruger22C]

I get around 81-85c (I forget now) with 35% fan using a single card, but the same settings; same resolution, etc.

When I run Crossfire however, temps go to 89c and 90% fan. (This is in BC2)

Any idea why? Also, this is the bottom card which isn't being moved, and is not restricted by the above card.

Thanks.