An Englishman's perfect summer suit is the iconic utilitarian drill in khaki or white. It served many a colonial administrator and diplomat well for over a century and is still the suit to work up a summer sweat in! Made unlined and machine washable they are as utilitarian as they need to be for everyday wear and frequent cleaning. You may not be in Havana but it looks cool in Soho too.
Bayo and Bertie Miller both in Pokit drill cotton suits