So please stop complaining, put a hat, pull your bootstrap and go back to the construction site. And try not to fall in the ground because you might get a third degree burn on the asphalt and we can't afford a replacement since nobody want to work anymore.
The Nordhaus estimates were always known for having limited utility for large changes in temperatures.
They assumed that damage to a sector wouldn't matter much if it was currently a small part of the economy. For example, if agriculture was 2% of the US economy, and agricultural output went to zero, the result would be 2% damage to GDP. The real world doesn't work that way though: people who are starving to death don't work, so GDP would go to zero in that case.
Either that, or the deaths and heat-related disinterest (read: giving up their skill or never getting into it in the first place) that causes the worker pools to dwindle. Cooled suits won't totally fix that issue, because it will be another hurdle that people will need to get past. Which is already a huge thing with many skills that people probably never have a chance to try due to cost or setup requirements.
I really hope this triggers the ruling class to care but I get the feeling it'll be thrown on the pile of other "investments that make money" along with healthcare, working public transit, proper electrical grid, and free college. 🙃
I sense a certain billionaire is going to propose construction workers should only work night shifts and that's why his silly ten sign is glowing like Ashalim Power Station