I have a First generation Pajero 2500 model Super wagon which is equipped with a 4d56 engine. I would like to know/verify which really to follow when setting the valve clearance.

This is what is really written.

On the engine:
Valve clearance (WARM)
in: 0.25mm
ex: 0.25mm

On the service manual:
Standard Value: On A COLD Engine
in: 0.15mm
ex: 0.15mm

so which would i follow?...
please someone really explain it to me. What is the meaning bet. cold & warm. i'm afraid that i might ruin the engine.