The Xperia 5 II may not feature a vapour chamber cooling system, but Sony has attempted to keep its latest flagship cool in other ways. Multiple pieces of graphite film should help prevent overheating, while the Xperia 5 II looks simple to repair too.
https://www.notebookcheck.net/Xperia-5-II-teardown-reveals-Sony-s-innovative-cooling-decisions.498290.0.html