Heat index in NJ will reach triple digits this week. See how hot it will get

A heat advisory remains in effect until 10 p.m. Tuesday, with heat index values expected to reach up to 104 degrees, according to the National Weather Service.

The advisory includes Bergen, Essex, Passaic, Union and Hudson counties.

An extension of this advisory through Wednesday may be necessary, the weather service's meteorologist Lee Robertson said. "There is a 30% chance of showers and thunderstorms on Monday and Tuesday, with a greater chance of rain on Wednesday."

Temperatures are expected to range from 98 to 100 degrees on Tuesday, the highest so far this summer.

The weather service warned that the elderly and those with chronic health problems or mental health conditions are at an increased risk due to the heat. Homes without air conditioning can be much hotter than outdoor temperatures.

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"Use air conditioning to stay cool at home or go to a place that has air conditioning," the weather services advises. "If you don't have home air conditioning, continue to seek out cool spaces each day as long as it remains hot, and for a few days after if your home is still hot. Check on vulnerable friends, family members, and neighbors," read the statement released by the service.

To reduce health risks while working outdoors, the Occupational Safety and Health Administration recommends scheduling frequent rest breaks in shaded or air-conditioned environments. Anyone overcome by heat should be moved to a cool and shaded location.

"Heat stroke is an emergency," the statement said. "In cases of heat stroke, call 911."