I let my 986 sit for about 30 seconds after startup, and I avoid revving the engine over 3000RPM until the coolant temp is near the 180 mark. I do this year round anyway, but it is especially important as it starts to get colder.
Also, be very careful about putting your top up or down, if you have a plastic window, below 70° F without heating it up in a garage or in the sun.
