It is the second year in a row that a heat wave has hit the New York City region earlier than usual, as global warming is projected to worsen heat waves and make them more frequent, climate experts say.

"Whatever was already going to happen ... all that is still going to happen. But when it happens, it's going to be worse." Extremely dangerous heat wave breaks temperature records last seen in 1888 — here's what you need to know about this potent heat dome first appeared on The Cool Down.