Running Furmark in mid-30s ambient temperatures is lunacy. Remember, 86-88 degrees is just a 50C delta at that point - which is rather normal for air cooled cards when gaming, and certainly when running a power virus load. Furmark also tends to run at lower clocks on modern cards due to the nature of the workload (though still often with higher than normal power draw - power limit throttling is mostly the reason for the lower clocks), which would be exacerbated by the high ambient temps. Remember, your 88 degrees at 35 degrees room ambient is someone else's 73 degrees at a 20 degree room ambient. 73 degrees (in Furmark!) is a relatively cool-running card. So, if you live in a place that hot, invest in a card with cooling built to match, or learn to live with some mild thermal throttling. Also, case ambient - even in a case with good airflow - is likely to be at least 5 degrees (often 10) higher than room ambient. Improving airflow through the case can help bring case ambient closer to room ambient, which might help GPU temps.