New York City experiences hottest June day since 1966

The hottest it has ever reached in Central Park was 106 degrees, on July 9, 1936. Just by reaching 97 degrees in the afternoon, Mr. Ramsey said, Central Park had already surpassed a record for the date that had stood since 1888.

Cold air doesn't clash with hot air as dramatically, so the jet stream calms down and drifts further up towards the pole. As the jet stream buckles and slows, this can allow high-pressure systems to move into an area. As we've seen, these high-pressure systems can cause a heatwave.

A wet sheet can help your body cool down at night. The best solution during a heat wave is to avoid being outside during the hottest parts of the day and staying inside as much as possible. If you do have to be outside, drink water — and then drink more, and more. Also, wear a brimmed hat.