I'd see if you can isolate where the sound it coming from first. I could see the pedal potentially being squeaky if the bushing is wearing out, but I would think that might do it regardless of whether it's warm or hot. I know on my mom's 94 the clutch pedal pivot rides on a plastic bushing that was pretty squished in her case. I bought a brass one at the hardware store and sanded it down to fit to try to provide something a little stronger for the future.