Yes, and the One has that heatspreader connected to the aluminum backplate through a copper tape, so the backplate serves as a secondary heatspreader:
Unlike most designs, the battery stands between the motherboard and the screen.
I wouldn't be surprised if the results showing the One surpassing the S600 GS4 in some benchmarks despite using lower binned SoCs with lower clocks, older Adreno drivers and slower RAM exist only because the One hardly ever throttles down due to overheating.
It also means the One should be a very stable device for overclocking, at least to GS4 speeds.