When I visited Singapore most people retreated indoors to the AC from about 2:30-4:30 every afternoon. I don’t recall the exact temps then but the idea that everyone would be just fine in a severe heat wave leading to power grid outages is false.
I don't make any sort of claim of 'just fine'. I am saying there will be places and times where people cannot regulate their body temperature via evaporation, so they will die outside without AC within hours. And in Singapore that point hasn't been reached yet.
The point isn't that it's "just fine" right now, it's that it will get way worse.
And given that the maximum ever temperature in Singapore is 35-36 for most months, I doubt that a wet bulb temperature of 35+ is common.