in my opinion, a lot of folks won't take climate change seriously until it adversely affects their way of life in such a dramatic way that they cannot deny it any longer. A wet bulb event, occuring over multiple hours, would be that signal. Piles of dead bodies from folks who either were misinformed or weren't able to move to safety would be quite the wake up call.
The 1896 New York heat wave lasted 10 days and killed ~1500 people. And has just 2 short paragraphs in Wikipedia ( https://en.wikipedia.org/wiki/1896_Eastern_North_America_hea... ) > "This was 10 days [with temperatures reaching] 90 degrees at street level and 90 percent humidity, with temperatures not even dropping at night," https://www.npr.org/2010/08/11/129127924/the-heat-wave-of-18... It wasn't necessarily a wak…
Seems like in this case most of the mortality was due to young men who had no choice but to work in those conditions. This event, among many other work-related disasters of the time, probably helped spur the push for better working conditions during the Progressive Era.