As potentially record-breaking daily temperatures approach, much of Oregon and Southwest Washington will be under excessive heat watches and warnings from Thursday through at least Sunday.

The National Weather Service in Medford is warning that temperatures in Jackson and Josephine counties could see daytime highs of 110 to 115 degrees. An excessive heat warning is in effect from 8 a.m. Thursday through 9 p.m. Monday.

A similar warning is in effect west of the Cascades from Southwest Washington to areas of Linn County from noon Thursday until 11 p.m. Sunday, with temperatures up to 105 degrees expected.

North central and northeast Oregon could see triple-digit temperatures from noon Friday through 10 p.m. Tuesday.

Meteorologist David Bishop with the National Weather Service in Portland said low temperatures won’t offer much relief.

“Overnight temperatures will also be very warm and that will limit the chances of recovery from the daytime heating,” he said. “With overnight lows ranging from the mid-60 to the low-70s.”

He says people should stay in cool, indoor spaces if possible, especially between noon and 6 p.m. Anyone who needs to find a cool place can call 211 or visit 211info.org.

Bishop also urges people to stay hydrated, “and that means drinking water, water and more water.”

Emergency coordination center

Gov. Tina Kotek’s office announced Wednesday afternoon that the state’s Department of Emergency Management is standing up its emergency coordination center in advance of the heat wave.

State agencies will be meeting daily to discuss the situation on the ground, and whether to send additional help to hard-hit pockets of the state.

”I strongly urge all Oregonians to practice extreme caution this weekend, stay cool, and take preventive measures to reduce the risk of human-caused wildfires,” Kotek said in a statement.

Since her election in 2022, Kotek has not declared a state of emergency due to high temperatures, as her predecessor Kate Brown did in both 2021 and 2022. Such declarations can make it easier for state agencies to send assistance and typically come after counties grappling with heat request help.

Kotek’s announcement said agencies are already working with local officials to prepare to open cooling centers for the public.

Health officials warn of heat-related illnesses

Dr. Matt Williams, an emergency medicine doctor at Providence Hospital, says the biggest things to watch out for during a heat wave are signs of dehydration.

For most adults, this includes dry mouth, tiredness and dizziness. For babies, signs include little to no tears when crying and a decrease in wet diapers in a day.

”Start preparing today, start hydrating, get the 2 to 3 liters of water in,” Williams said on Wednesday afternoon. “It’s also a great time to look out for one another and check in on family, friends and neighbors.”

He said one of the most common mistakes people make during heat waves is underestimating just how hot it can get.

As temperatures get into the triple digits, Williams said people can experience different types of heat-related illnesses that can range from a mild rash to conditions more severe.

Williams said a top concern is heat stroke, as it is life-threatening and can happen as your body temperature rises above 101 degrees Fahrenheit.

”Once we’re outside of that range, nothing works like it’s supposed to,” Williams said. “Our brains don’t function properly, which is where we get the changes in behavior. Our hearts have to work harder to try to cool us down and pump blood throughout the body. Anytime we’re stressing that cardiovascular system, chances for a stroke go up as well.”

Officials are hoping to avoid a repeat of 2021′s deadly “heat dome” event, which claimed the lives of almost 100 Oregonians. More than 70 deaths were reported in Multnomah County.

Related: Pacific Northwest heat wave was a freak, 10,000-year event, study finds

Portland metro area preparedness

Multnomah County Chair Jessica Vega Pederson has declared a state of emergency effective noon Friday as forecasters predict a record-setting heatwave this weekend.

The declaration comes after the National Weather Service issued an excessive heat warning for the county with temperatures expected to exceed 100 degrees on Saturday and Sunday.

According to a press release, since Tuesday the county has worked with several nonprofits to contact vulnerable community members, including those experiencing homelessness.

Although cooling centers have not opened yet, county officials said they are in discussions on when to do so. It’ll likely be announced the day before the county determines the threshold has been passed.

“We’re preparing for a long, very hot weekend, and you should, too,’’ said Chris Voss, the county’s director of emergency management. “We’re lining up locations for cooling centers, recruiting staff and developing plans. Everyone should be thinking about how they can keep themselves cool, and making plans to support friends and family who might need help.”

Multnomah County Health Officer Dr. Richard Bruno also warned that people’s bodies may not have yet acclimated to the heat given there have only been a few hot days so far this year.

“I’m particularly worried about the thousands of people heading to music festivals and sporting events this weekend,’’ Bruno said. “They’ll be spending a long time outside, may have little access to shade and water, and may not recognize the risk.” The emergency declaration will last until noon Monday.

For the latest information from Multnomah County on its cooling shelters visit here.

Burn bans issued

Portland and Clark County have issued burn bans to reduce the risk of accidental wildfires caused by the soaring heat.

That means no residential burning or clearing of any vegetation will be allowed.

Clark County’s ban will start Friday and last until September, according to a news release.

Portland Fire and Rescue spokesperson Rick Graves said the burn bans typically last until October. He said they occur annually, but the department has been issuing them earlier in the year given the warmer temperatures.

”We know that open flames lead to embers flying into the air and dropping down into dry vegetation and starting fires,” Graves said.

Portlanders can still use grills of all types during the holiday weekend, but fire officials are urging caution — any ashes should be disposed of in a metal container away from combustibles, and grills should remain 10 feet away from fencing or bushes.

Those who violate the burn ban will be forced to extinguish their fire, Graves said.