I'm not sure if you're asking how to keep your mod cool or how to keep the vape cooler when using.
As for the former, keep it out of the sun. I some times use a foam can holder to keep my mod and a bottle of
juice from falling in the sand or dirt. I suppose it would shade it as well, in any case, just keep it out of direct sunlight.
If it's a cooler vape you want, just turn down the wattage although you may want to go for a higher resistant coil.
You may want to have something to keep everything in that will keep the sand out as well, Ziploc bag perhaps.