At what temperature will the Pi's processor work fastest?
On your laptop it's not the temperature itself that slows you down, it's the processor overheat protection, that lowers the CPU frequency to avoid burning it out.
In case of RPi, the best temperature is the room temperature, with not very high humidity. If you want to make RPi processor run faster, run
raspi-config and check overclocking options, just don't go too high and stay safe.