Inside and air con on hot days are probably a good idea for first couple of years till you aclimatise re 'hot tips' just the usual fine attention to engine seals, foam to body, plugs, any and all gaps/holes in tinware, clean engine and gearbox, shield between muffler and engine tinware,all tinware including push rod tube covers in place, if heater pipes not in place ensure holes are blanked off,[best if heater box fan is connected so that cooling air can be passed thru boxes and reduce radiated heat to heads.],good oil [thats basis for a lot of opinions ] Oil temp guage Ensure cool air to carb intakes Usual attention to timing,tappets and carb tune once it gets over 38C cooling can get a bit more touchy so drop in speed to suit can be benificial. Additionals As I dont have an original heat shield over muffler I have made substantial shielding with metal/ceramic turbo shielding. Also insulated inside of tinware in the area where air travels to fan intake[type 1V engine] opening front door windows disturbs [negatively]air flow to engine intake vents head temp guage if you are realy worried but I just check plugs for base info and know if things are hotter than usual. i also have hand held infra red thermometer. clean fan and shroud. painting fan and interior of Al shroud should give slightly better flow. picky but easy to do if its apart for any reason. POR 15 suitable product. high temps are only a few months, easiest to adjust hwy speed for any realy hot days. other than that ,an engine with everything in place and well maintained shouldnt suffer to much. a cooling run down for last 10 km is also a good idea.