Very high temperatures over several days with temperatures that do not drop at night cause the temperature of the tarmac to rise by several dozen degrees (on the surface), which put severe strain on the underground networks.
New York City's energy grid is working overtime to keep up with demand that is rising more quickly by the day because of electric devices, electric vehicles, and AI. That puts the city at real risk for more blackouts, like we saw in 2019, and that risk will only grow.
The Iberian blackouts show how everybody across society can contribute to protecting a nation against disruptive events, according to the government's resilience plan.