Brooklyn is bracing for its first heat wave of the summer bringing oppressive temperatures that could be dangerous if not taken seriously.

City officials are warning New Yorkers that today marks the start of the first heat wave of the summer, meaning temperatures will climb into the 90s for three or more days this week.

Local doctors say to be aware of heat exhaustion and heat stroke. Heat exhaustion typically presents with dizziness, thirst, heavy sweating and nausea.

Thankfully, seniors in Williamsburg have not only found a safe space to cool off - they're having fun too. Brooklyn residents were at Swingin' Sixties air conditioning on full blast, fans, and lots of food and water to go around.

Senior resident Aida tells News 12 she's thankful for places like this, as she's still waiting on her AC unit to be installed.

People are encouraged to stay inside in air conditioning and to avoid activity outdoors. If you do not have access to air conditioning, you can visit one of the city's cooling centers.

To find a cooling center closest to you, click here.

MORE: 13 cool tips to help you stay healthy during the summer heat

New York City beaches are also open from 10 a.m. to 6 p.m. Public pools are not open yet – with openings scheduled for June 27.