A number of bodies have been found in the Nevada desert because of IR. I'd say that's at least as hot as Aruba.
That's why it's rare to hear of someone dumping a body out in the desert there these days (among other reasons).
And cool at night (unlike the island). Ever heard the saying "Cool desert nights"? Very little temperature variation between night and day in the tropics. That's what you're relying on.
Did they ever find Bishop Pike in the desert?