See Delaware heat index map as heat wave causes record-breaking temps across Northeast

It's going to be a sweltering week across the Mid-Atlantic.

The heat index is going to rise as a prolonged heat wave is set to bring record-breaking high temperatures across the region.

See where the index is in Delaware:

Delaware heat index map

What is the heat index?

The heat index is what "the temperature feels like to the human body when relative humidity is combined with the air temperature," according to the National Weather Service. The combined reading of temperature and humidity is a better estimate of how the human body is feeling the heat.

"When the body gets too hot, it begins to perspire or sweat to cool itself off. If the perspiration is not able to evaporate, the body cannot regulate its temperature. Evaporation is a cooling process ... When the atmospheric moisture content (i.e. relative humidity) is high, the rate of evaporation from the body decreases. In other words, the human body feels warmer in humid conditions," according to the weather service.

This article originally appeared on Delaware News Journal: See Delaware heat index map as heat wave hits Northeast