In general, heat is the enemy of electronics. [Christopher Barnatt] is serious about defeating that enemy and did some experiments with different cooling solutions for the Raspberry Pi 3. You can see the results in the video below.
A simple test script generated seven temperature readings for each configuration. [Barnatt] used a bare Pi, a cheap stick-on heatsink, and then two different fans over the heatsink. He also rigged up a large heatsink using a copper spacer and combined it with the larger of the two fans.