Note that there are two common "wet bulb" temperatures used in discussion:
Wet Bulb Globe Temperature - this tells you that physical activity (including work) in unshaded locations can kill healthy adults and is used in this article
Wet Bulb Temperature - this tells you whether it is hot enough to kill the bulk of the population for just sitting still in the shade with access to plenty of water
A Washington Post analysis found that the wet-bulb globe temperature, which measures the amount of heat stress on the human body, reached 97 degrees to 100 degrees (36 to 38 Celsius) in Delhi on Tuesday. That is higher than the 89.6 Fahrenheit (32 Celsius) threshold that researchers have identified as posing a risk to human survival if such heat is prolonged. The wet-bulb globe temperature is based on a combination of factors including temperature, humidity, wind and clouds, and was calculated by The Post using data from a nearby weather station.
Yup, but it's possible to slow that rate and (if we're smart and motivated) geoengineer ways to reverse it.
Again, though, it would require the rich to make less money.
But yes, in general I agree with you; even if we pull out the stops we're already locked into some kind of increase, but that worse part is that it seems like we're going to do is go hell-for-leather because the rich don't have all the money yet.
In the long term - dig in and design heat shelters, most likely. Because it's cooler underground and heat waves will pass. When a bad one comes, people would stop working and find shelter from it. One can even accumulate cold in a thermal store during cool periods and distribute the cooling effect to premises during heat waves.
In the short term - those who can (there will be an equality and access problem) and those who must (who cannot stop working) would install air conditioners and similar stuff.
Well, a heat wave cannot last forever. And in terms of cold storage - it's +30 C over here currently already for a week, it has been 1.5 months since the last snowfall - and the last pile of snow on the local airport is still melting. Darkened, not recognizable as the substance it used to be, but existing, without people making the slightest effort to protect it. :)