Temperatures could hit 100 degrees Monday and Tuesday — a level of heat that Philadelphia hasn't reached since 2012.
The city's spraygrounds, pools and public cooling spaces are great ways to beat the heat. On Friday afternoon, the city declared a heat emergency for Sunday afternoon through Wednesday evening, which extends the hours of some cooling spaces and adds air conditioning stations at some rec centers.
MORE: If Philly hits 100 degrees next week, it would be the first time it reached that mark since 2012
But people who need to be at home, for work or any other reason, are stuck trying to keep their homes as cool as possible — hopefully without getting an eye-popping energy bill in a few weeks.
To help, here's a comprehensive guide to cooling off your home, from the best methods for using fans to the ideal air conditioning temperature to how to handle cooking.
Keep the sun out
A key part of keeping a house cool is preventing it from getting hot in the first place. Re-insulating a home, or adding trees and greenery for shade are big projects. A quick and easy fix is to block out the sun by adding blinds or blackout curtains — and keeping them closed during the day. About 40% of unwanted heat buildup comes through windows, according to Ready.gov.
If you still desire transparency, install UV-blocking window film or awnings to allow some light in. If that's not an option, keep the blinds open on windows and doors that don't get direct sunlight, but close the ones that do.
If you're turning the air conditioning off after dark, when the temperatures drop, open curtains and blinds to make sure they're not blocking the cool breeze from entering the home.
Don't make your AC work harder
The key to keeping your home cool without overworking the AC is reducing the gap between outdoor temperatures and indoor temperatures, according to Thomas Hill, PECO's senior energy efficiency program manager. As the temperature gets hotter, it's better to raise the inside temperature slightly so the unit doesn't need to work harder than necessary. Set thermostats between 75-78 degrees for efficient cooling, and increase the temperature by 7 degrees when no one is home. That will ensure the system is still removing humidity from the air.
"Everyone's comfort level is different, so I would say try to make yourself comfortable at all times," Hill said. "However, we think the optimal temperature setting for a home is between 75 to 78 degrees."
When using central air conditioning, it's also important to make sure the registers aren't closed or being blocked by furniture. This maximizes ventilation.
When cooling large amounts of space, central air is more efficient than using several window units. But if that's not an option due to a lack of duct work or large upfront costs, Hill recommended purchasing an energy-efficient tower or window units. Make sure they have the right amount of BTUs— British thermal units — needed to cool off the space.
Maintaining the system also is important, and Hill recommended starting the summer by servicing it to make sure it's in top shape. PECO recommends maintenance once per year, noting it can lower energy consumption by 5-15%. Filters should be changed or cleaned regularly. If you have central air, make sure nothing is blocking the outdoor unit, but plants and shrubs in the area can be used to provide shade to the unit.
"When the sun is hitting that in the summertime, it actually makes it work harder," Hill said. "So, by casting some type of shade on the outdoor unit, (it) will actually make it work better and more efficient and more effective, as well."
Use fans effectively
Fans are the cheapest and most efficient way to cool a home, Hill said, because they only cost about $0.01 per hour to run. Ceiling fans are the best at circulating air — they should run counterclockwise to push cold air down — but box fans can help with targeted air flow. Fans should be pointed toward people to maximize the effects of the breeze.
"When you have a fan blowing that air across your body, it actually feels a lot cooler, it makes you feel more comfortable," Hill said. "So use fans in conjunction with air conditioning."
However, if the inside temperature is above 90 degrees, fans can make people feel warmer by circulating hot air. In that case, fans only should be used to blow hot air outside or to bring in cooler air from a different space.
Humidity levels can impact the temperature of a home, too. A dehumidifier can help remove some of the moisture from the air. However, Hill cautioned that they often use about as much energy as a smaller air conditioner.
Trap cool air inside
Once a home has cooled off inside, it's important to make sure the air doesn't escape. Double check that windows are closed, add weather stripping around windows and doors for a better seal, and close up any cracks with caulk. Storm windows — thinner windows that can be installed over existing windows — provide additional protection. It's also good to check for any holes in a home's siding, and to ensure that exterior wires are sealed properly.
If you have an uninsulated garage or attic, add a thermal barrier between that space and air conditioned ones to prevent hot air from seeping in. The U.S. Department of Energy has a guide to doing this yourself. If it's within your means, consider insulating those spaces to keep them from getting so hot in the first place.
During the day, close the doors to the hottest rooms so the warm air stays in that area. If you're using a window air conditioner in just one room, shut that door so cold air doesn't escape. For central air, Hill recommended partially shutting off the vents to rooms that aren't used often, so more pressure goes to the rooms you want cooled.
Make changes to the way you cook
During a heat wave, avoid using the oven or stove during the hottest part of the day. Make fresh foods that don't require cooking or use crockpots and air fryers, which don't exude as much heat.
If cooking is a must, grill outdoors to keep the heat away from the house and bake and sauté at night, when it's cooler.
Other heat-producing appliances, such as dryers and dishwashers, should be run at night or early in the morning.
Be prepared for power outages
There is an increased risk for power outages, because many people will be running their air conditioning for extended periods of time and there is a possibility of storms.
PECO recommends turning off unnecessary lighting and devices to avoid overheating the AC system. Try to keep phones charged and have a plan to check in on loved ones if there is a power outage.
Recognize the signs of heat-related illnesses
A heat wave puts people more at risk than one particularly warm day. People are at higher risk for overheating if they have heart disease, mental illness, poor blood circulation or use medications that make it hard to regulate body temperature.
The city recommends people learn the signs of heat-related illness to recognize when someone needs medical attention.
To keep bodies cool, avoid strenuous activity during the hottest part of the day, which is usually 10 a.m. to 2 p.m. People who need to work outside should try to stay in the shade or create shade with an umbrella or tarp. Because sunburn can raise body temperature, it's important to wear sunscreen and reapply as necessary.
The city's Heat Vulnerability Index allows people to see how vulnerable their blocks are to heat-related illnesses and to find the closest cooling centers, pools and spraygrounds. People with limited mobility are advised to call 311 before heading to a cooling center to ensure it has appropriate accommodations.
How to get help paying electricity bills
Pennsylvania's LIHEAP program helps eligible households cover the cost of heat during the winter, but it does not cover air conditioning.
Pennsylvania has a Low Income Usage Reduction Program designed to help eligible households make their homes more energy efficient, thereby lowering their electricity bills.
PECO offers cooling rebates for installing central and mini-split air conditioning and has a customer assistance program that lets households pay a percentage of their total income as a fixed PECO bill.
Eligible Philadelphia residents also can apply for the Basic Systems Repair program, which provides free repairs in the event of an emergency. The Utility Emergency Services Fund grant program provides financial assistance to people facing potential service shutoffs.
Neighborhood Energy Centers are available throughout Philadelphia to help people apply for bill payment programs and provide energy counseling with information on conserving water and electricity.
For residents taking extra baths and showers to stay cool, the Philadelphia Water Department also has bill assistance for senior, low-income and other customers enduring hardships.