Don't worry about the cam and springs- the springs generate quite a bit of heat from the spring steel flexing- the oil is the only thing that keeps them cool. The biggest thing to worry about is the pistons coming "to temperature" and expanding to the correct size to fit the bore so you don't have ring flutter or break a ring land. That, and oil circulating through the system to keep everything lubricated.

Takes about 30-45 seconds for the motor to "come to temperature" for the internal parts that truly matter. NOW- WOT is a totally different animal- you want to wait until it is at full operating temerature before you stick your foot in it. Alot of people are under the misconception that you can just fire a engine up, wait a minute and go beat on it- It doesn't work that way. I know someone out there will say "well drag cars do it all the time"- they sure DO. However, they are built for their clearances to be "on the money" below 100 degrees because at the end of a pass, they might just be at 100-110 degrees. OEM engines are built with clearances and tolerances designed at the 195 degree mark. 20 degrees either way won't matter much, but dead cold would be a huge problem.

Those who do fire up a dead cold engine and romp it are shortening the life of the engine. Fortunately, there aren't many people out there that do that everyday anyway.