During a sweltering afternoon last month in Brooklyn, on a day when trudging along on the sidewalk felt like wading through shower gel, I walked into the original location of Di Fara, one of the country’s most famous pizzerias. It was well past prime lunchtime, around 2 p.m.

From all I’d read about the place, there should have been a line of people flowing out its door. But there was no wait — only three wilted-looking customers, nibbling on square slices, sitting at communal tables in the back of the small shop. New York heat waves will roast the appetite for pizza right out of most souls.