Weather Service on high temperatures: 'Do not take this threat lightly'

Crowds flocked to waterfronts and swimming pools on the East Coast and in the Midwest on Thursday to try to cope with a massive heat wave that has killed at least 22 people this week.

The National Weather Service issued excessive heat warnings for wide areas of the central and eastern United States, saying the combined heat and humidity could push the "real feel" temperature to 115 Fahrenheit (46 Celsius) through Saturday.

By Thursday afternoon in New York City, the thermometer hit 91 degrees (33C) but it felt more like 112 degrees (44C), according to AccuWeather.com.