Summer is off to a steamy start.
The National Weather Service has issued a heat advisory for the New York City area, in effect from noon Wednesday until 8 p.m. Thursday.
Temperatures are predicted to top 100 degrees, and the state Department of Environmental Conservation has also issued an air quality health advisory from 11 a.m. to 11 p.m. Wednesday.
"We all think we're tough, and nobody thinks that it's a big deal. But sadly, each year, we have to re-learn the lesson. This is a very big deal, and we should all be very careful," said Mayor Michael Bloomberg.
The heat advisory includes Lower Hudson Valley and northern Nassau County.
Officials are urging people to avoid strenuous physical activity, drink lots of water and stay out of the sun. New York City Health Commissioner Dr. Thomas Farley added "avoid alcoholic beverages and avoid caffeinated beverages. which can make you dehydrated."
Cooling centers with air conditioning, water, and places to sit will be open across the city and in Yonkers. People without air conditioning, older adults and people with chronic health conditions are most at risk.
Mayor Michael Bloomberg also encouraged people to check in on their elderly neighbors during the heat wave.
Con Edison, meanwhile, reduced voltage in some neighborhoods in Queens and Brooklyn due to problems "on electrical equipment," asking customers to curtail useage of non-essential appliances.
To find a cooling center in NYC, call 311 or visit nyc.gov.
Brian Zumhagen contributed reporting.