on paper,yes.but in the real world it can slightly (or greatly) cause more heat.on a higher compression motor the air/fuel charge burns faster,hotter & has a better thermal efficiancy,which makes it more power & better fuel milage,but then detionation may become a problem,so timming is often retarded,and that will build up heat.or CR & cams are not a good match,which will also build heat.so,sadly in alot of cases more heat is the result of going to higher compression.but a well thought out build with all components (cams,compression,combustion chamber/squish & ignition)working together,a slightly cooler or atleast the same temp motor will result.now that being said,since the air/fuel is being burt at a higher temp in a higher compression motor,the temp of the air being drawn in the combustion chamber has a direct affect also,so a higher compression motor will be affected in hotter weather more so that a lower compression set up