Attach a thermostatically controlled attic exhaust fan over an attic vent. Each end of the gable roof should have one.
Create your own flow of air out the vents by setting the fan thermostat to go on when the attic temperature rises.
Do not rely just on exhaust vents. When intake vents, such as those built into the eaves, are unavailable, you must have another way of circulating the hot air out of the attic.
Build a few ridge vents on top of the roof while your home is under construction, or you can install them later if need be. These ridge vents provide another way for attic air to escape.
Cut a properly measured hole through the shingles and roof decking.
Mount the vent in the center of the house right behind the ridge so it is unseen from the street.