Marble countertops are porous and susceptible to stains, but they aren't affected by heat.
Treat marble with a special stone sealer to reduce its porosity, and wipe up wine, fruit juice and other acidic food spills immediately to prevent permanent surface etching. Abrasive cleaners will mar the surface of marble, and oil polish and soft waxes may discolor it.
While many commercial cleaners are available, borax rubbed into the surface with a moistened cloth will also clean marble. Rinse with warm water, and buff dry with a soft cloth.