A friend of mine who lives in Queensland (Sunshine Coast) was talking about a recent spell of 32° and 100% humidity and how oppressive it was. My understanding is that such weather is not survivable long term [1] without air conditioning. A power failure would be disastrous. [1] https://www.psu.edu/news/research/story/humans-cant-endure-t...
It is scary - but I suspect the headline temperatures/humidity aren't the only story. We can build passive structures to regulate peak temperatures - caves and windowless insulated boxes with high thermal mass, for instance. As long as the average temperatures (day and night) over a few days or a week are survivable, active cooling isn't strictly necessary.
Its hot-dry climates where it gets cool overnight where thermal mass is most important (the thermal mass warms up during the day and radiates heat at night, when outside cools down).
In hot-wet climates, if you want passive comfort, your best bet is to make a big roof and then encourage cross-ventilation so the wind provides some cooling.