The National Weather Service has extended the heat advisory for New York City.

The advisory will remain in effect until 8 p.m. Friday as New Yorkers brace for the fourth day of blazing heat and humidity.

As a result, public schools will be limiting outdoor strenuous activity. To best prepare for the heat, pack plenty of water, stay in the shade, put on sunblock and wear light-colored and loose clothing.

Just because the temperatures may appear to be dropping, and there's rain in the forecast doesn't mean this weather is any less dangerous.

Symptoms of heat exhaustion and heat stroke include, heavy sweating, dizziness, clammy skin or nausea. Keep a close eye on your neighbors, pets and older folks as well.

Cooling centers are open across the five boroughs. They include libraries, community centers, senior centers, and NYCHA facilities. Click here to find a center in your area.