Oregonians braced for a major heat wave Friday as temperatures were expected to top 100 degrees.

The first heat wave of the summer may break records. Experts say intense heat and warmer-than-normal weather could lead to an active wildfire season. But the high temperatures also pose dangerous conditions now, especially for people experiencing homelessness, younger and older individuals, and animals, with both the city of Portland and Multnomah County declaring a state of emergency in response to the heat.

David Bishop, a meteorologist with the National Weather Service in Portland, said Friday morning that it was expected to be the first triple-digit day in a string of very hot days. Communities throughout the Willamette Valley are looking at daytime highs between 100-102 F. The highs are forecast to be even worse in other parts of the state, including up to 110 F in southern Oregon. As a result, Gov. Tina Kotek on Friday declared a state of emergency.

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Bishop said temperatures are expected to hit the triple digits for the next two to three days, likely even going into four days, and possibly hitting as high as 105 F on Saturday in the Willamette Valley.

Though the specifics may shift slightly, he said the models have held up this week — people preparing for 103 F are still preparing the same way if temperatures reach 105 F.

By Wednesday of next week, Bishop said, daytime highs should drop to the low- to mid-90s in the Willamette Valley.

“So, it’s still going to be warm,” he said, “but definitely much cooler than for the start of the week.”

The National Weather Service earlier this week put most of western Oregon and Southwest Washington under an excessive heat watch from Thursday afternoon to Sunday evening. Bishop said that’s been upgraded in some areas to an excessive heat warning.

Heat watches are used when the risk of a heat wave has increased but its occurrence and timing is still uncertain, according to the National Weather Service. This is the phase to “be prepared.” But a heat warning is the time to “take action.” A warning is issued within 12 hours of the onset of extremely dangerous heat conditions.

Bishop, speaking for the northwest region of Oregon, said Friday morning that the areas currently under an excessive heat warning are the areas west of the Cascade foothills but not including the coast. This includes the Columbia River Gorge and Hood River.

Excessive extreme temperatures, whether they’re hot or cold, affect those that are more sensitive to extremes, Bishop said.

“Typically, those individuals are the very young and those that are well-seasoned,” he said, “you know, that have been around for a little while.”

Related: Most of Oregon and SW Washington under excessive heat alerts

Pets and animals are also at heightened risk. That includes birds and dogs.

“Be aware of the surfaces that they’re walking on,” he said, “because concrete and asphalt, those can get blisteringly hot.”

Everyone also needs to hydrate.

“And what we mean by that is: drink water, drink some more water, and then go drink some more water,” Bishop said.

Avoid going out during the hottest parts of the day, he advised, typically around midday to 7 p.m. For people without air conditioning, Bishop recommended people check with their local governments to ask where cooling shelters are.

“I just want to reiterate: people, be careful,” he said. “If you can look out for your neighbors, look out for your friends, you know, and at least be aware of the signs of heat exhaustion and heat stroke, and if you see those signs, do not hesitate to call 911.”

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Service groups pass out water, information to those in need

People experiencing homelessness are at especially high risk.

Tara Slak, an outreach supervisor with Transition Projects, was out with her small team Friday morning distributing water and other materials at encampments near Portland’s Union Station. In addition to providing water, Slak said the key is making sure people know of the dangers.

“They don’t have a TV, so they don’t even watch the news. So they don’t even know what’s coming,” Slak said.

Those who stopped by picked up as many bottles as they could carry, along with Gatorade packets and cooling rags — anything to help them survive the next week of brutal temperatures.

“We don’t really have a way to prepare, we’re all in tents,” said a woman named Trinity. “I was hoping to find a battery-powered fan, but I can’t find any at the shelters.”

The city is pausing all work related to removing homeless encampments during the heat emergency, according to Mayor Ted Wheeler’s office.

This comes less than a week after Portland announced it would begin enforcement of new public camping rules, which threaten fines and jail time for people who violate the new restrictions.

The city has not penalized anyone for violating that policy yet, according to Wheeler’s office.

Multnomah County has opened three cooling shelters for people to use, with plans to open a fourth tomorrow at Congregation Beth Israel in Northwest Portland. For a more complete list of cooling resources, check here or call 211.

As early as noon Friday, people began streaming into the cooling shelter at Cook Plaza in Gresham. Sherri Thompson fanned herself as she and her dog sat next to the huge air conditioning unit. The air conditioning in her car is broken, she said, and she’s come to rely on these shelters for all kinds of extreme weather, be that heat or last winter’s ice storm.

“It’s too hot out there for anybody,” Thompson said. “Everyday (the shelter) is open, we’ll be here.”

Reporter Alex Zielinski contributed to this story.