The worst heat wave of the week will hit Southern California in the next few days.

forecast

Meteorologists say temperatures in the San Fernando Valley could be between 110 and 115 degrees Fahrenheit. Burbank, Woodland Hills, Pasadena, Santa Clarita and Palm Springs could also see triple-digit temperatures. And downtown Los Angeles is expected to see temperatures between 95 and 115 degrees.

Temperatures in Long Beach are also expected to be between 35 and 40 degrees, said Mike Wofford, a meteorologist with the National Weather Service in Oxnard. Inland Orange County, temperatures are expected to be in the 30s, and in parts of inland San Diego County, temperatures could reach as high as 39 degrees.

Temperatures are expected to reach triple digits elsewhere in the Southland, too. Santa Clarita could see 41 degrees and Palm Springs 48 degrees by Thursday. And in the Inland Empire, temperatures could reach 45 degrees.

Read more: Extreme heatwave hits Southern California. How bad will it be?

Warnings

The weather service issued a heat warning for most of Los Angeles County, lasting from 11 a.m. Wednesday to 8 p.m. Friday. The population was warned of peak temperatures of 35 to 43 degrees Celsius.

Nighttime temperatures between 21 and 25 degrees Celsius are unlikely to provide much relief from the heat.

Timeline

Wednesday: 94 in Downtown LA; 80 in Santa Barbara; 110 in Woodland Hills

Thursday: 97 in Downtown LA; 82 in Santa Barbara; 113 in Woodland Hills

Friday: 95 in Downtown LA; 82 in Santa Barbara; 111 in Woodland Hills

Saturday: 93 in Downtown LA; 80 in Santa Barbara; 108 in Woodland Hills

Fire hazard

Officials also warn of an increased risk of fire during the scorching heat.

There is one bright spot, however: the extreme temperatures are not accompanied by Santa Ana winds, reducing the risk of wind-driven, fast-spreading wildfires.

Read more: July was the hottest month in California as the climate reaches dangerous new extremes

Security

Los Angeles Mayor Karen Bass announced this week that hundreds of cooling centers will be open across Los Angeles by Friday, including “climate stations” on Skid Row where people can find shade, seating and cold drinks.

Citizens can find a list of cooling centers and “climate stations” on the Internet.

Sufficient fluid intake

Drinking more water than usual before you feel thirsty will help you stay hydrated. When you’re outside and sweating, you should typically drink two to four cups of water – or about 16 to 24 ounces – per hour.

Dr. Fausto Farfan, director of the emergency department at Kaiser Permanente Woodland Hills Medical Center, also recommends adding electrolytes to water or drinking sports drinks to help the body replace salt and minerals lost through sweating.

One way to tell if you’re adequately hydrated is to pay attention to your urine. If it’s dark yellow or brownish, that’s a sign you need to drink more fluids.

“Usually, the rule of thumb is that if you’re drinking enough fluids, your urine should be a light yellow color,” Farfan said. And if you’re urinating less than normal, it’s probably time to drink more.

According to the U.S. Centers for Disease Control and Prevention, heat-related illnesses range from sunburn and heat rash to more dangerous conditions such as heat exhaustion and heat stroke.

Read more: How to stay cool and safe during California’s first heatwave of the summer

Do you know the symptoms of heat-related illnesses

Signs of heat stroke, the most serious of all heat-related illnesses, include a body temperature of 102 degrees Fahrenheit (39 degrees Celsius) or higher, a rapid, strong heartbeat, hot, red, dry or clammy skin, headache, dizziness, nausea, confusion and fainting. If you or someone you know has these symptoms, seek medical attention immediately. In the meantime, the CDC advises moving to a cooler place and lowering your body temperature with cool towels or a cool bath, but not drinking anything.

According to the CDC, signs of heat exhaustion include heavy sweating, cold, pale and clammy skin, a fast, weak heartbeat, nausea or vomiting, muscle cramps, tiredness or weakness, dizziness, headaches, and fainting. If you have these symptoms, go to a cool area, loosen your clothing, put on cool, wet clothes, or take a cool shower and drink water in small sips.

Get medical help right away if you vomit, your symptoms get worse, or if they last longer than an hour.

Protect the most vulnerable

Children, pets, the elderly, the homeless, pregnant women and people with chronic illnesses are more susceptible to heat-related illnesses.

Farfan said they essentially require the same safety measures as everyone else, but it’s important to check on them, “like we have some kind of buddy system that keeps an eye on them in case they don’t realize they’re starting to overheat.”

If you notice your pet turning red, sweating excessively, having difficulty moving, or showing other symptoms of heat-related illness, bring him some water and help him move to a cooler place.

And never leave a child or pet in the car. Even with the windows open, temperatures can quickly soar.

Read more: Heat wave in Southern California brings temperatures of up to 48 degrees Celsius

Stay informed

Los Angeles residents can sign up for heat alerts on the city’s website. You can also check the weather forecast for your area on the National Weather Service website and find weather watches, warnings and advisories for California and beyond on the National Oceanic and Atmospheric Administration website.

More tips to stay cool

• Eat foods high in water content, such as watermelon and cucumber, but limit or avoid sugary, alcoholic and caffeinated beverages.

• Wear loose, light-colored clothing and hats for protection.

• Keep pets indoors if possible. If you must keep them outside, make sure they have plenty of shade and water.

• Take a cold shower.

• If possible, avoid using stoves, ovens or other appliances that generate heat.

Sign up for Essential California to get news, features and recommendations from the LA Times and beyond delivered to your inbox six days a week.

This story originally appeared in the Los Angeles Times.