And if you dont have a heatsink and fan of sorts just use alternativing fingers on the cpu, they can still absorb about 10-15 DegC off the cpu temp and thats overclocking a 3b in the 1.35Ghz range. Surprisingly robust. Sadly cant get it to idle below .6Ghz yet, that needs more work.

But it makes wonder how much more phone manufacturers could squeeze out of their phones, although Apple are definately overclocking the 15.