WASHINGTON - The National Weather Service has issued an excessive heat warning until 9 p.m. for much of the D.C. area.
Temperatures will be near 100 degrees, but it will feel like 110 to 115 degrees.
The combination of heat and humidity will make for dangerous conditions and the possibility of heat-related illnesses. Here are the signs of heat illnesses.
Hyperthermia, or over-heating, is a concern in this weather. Doctors say the old, young and those with weaker immune systems are especially vulnerable.
According to the National Institutes of Health's National Institute of Aging too much heat is not safe for anyone.
"It is important to get relief from heat quickly. If not, you might begin to feel confused or faint. Your heart could become stressed and stop beating," the website states.
Metro responds to heat wave
Metro customers will be able to carry and consume water on the trains through Monday. The exception to Metro's "no drinking" policy is in response to the extreme temperatures.
All scheduled track work for the weekend will continue and service will be affected on the Orange, Blue and Red lines.
It's also recommended that those who will spend time outside in the heat eat smaller meals. Doctors suggest people make sure to drink plenty of water, stay out of direct sunlight and wear light, loose-fitting clothing.
Monitor for signs of heat exhaustion and heat stroke. If you're not feeling well, get to a cool, well-ventilated place.
During extreme heat conditions, vans from the United Planning Organization canvass areas throughout the District looking for people suffering from the heat and transport them to cooling centers.
Police recommend children and pets be kept inside and not left in cars. The Prince George's County Fire Department suggests if you leave a child or pet in the car, that you also leave your purse or cell phone so that you'll be reminded to return quickly.
For those who don't have air conditioning, make sure air is circulating at home by using fans and opening windows. Use ice packs and cool water to reduce body temperature.
D.C. also provides free cooling centers for people to use in extreme weather.
In this kind of heat, it's best to take pets for a walk in the morning or late evening when temperatures are coolest, says Dr. Katy Nelson, an Alexandria-based veterinarian.
Limit your pet's outdoor exercise and play and always keep water available. If you do leave your pets outside, Nelson suggests having a cool, shady spot and plenty of water.
"If you have the option of putting them in the air conditioning, that's probably the best option," she says.
She emphasizes: "Never ever, ever leave them in the car."
The District's Parks and Recreation Department is extending the operating hours of certain pools through the weekend until 8:30 p.m. and 9:30 p.m., depending on the location. Though the pools will be open late, the department suggests residents limit their time outside.
"It is our hope that District residents will remain inside as our city prepares for the second heat wave of the summer," said DPR Director Jesús Aguirre.
The District lists the hours and locations of public pools for residents to cool off.
D.C. DMV Inspection Hours Change
The Department of Motor Vehicles is changing its inspection station hours on Friday, June 29 and Saturday, June 30 in response to the high temperatures. The inspection stations will be open from 5 a.m. to 1 p.m. on these two days.
WTOP's Megan Cloherty contributed to this report. Follow WTOP on Twitter.
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