When visiting Okinawa, that is when my family and I invested in using umbrellas while simultaneously using our portable fans while we walked around the city! Using umbrellas during the daytime was extremely normalized and even encouraged to block the sun, which is extremely different from how it is in San Diego. Both the fan and umbrella helped tremendously, though my family and I would go into the convenient stores as a slight break from the heat because all buildings had AC blasting!