For much of this week, nighttime temperatures have dipped below freezing. Some churches and community centers in Portland have transformed into emergency overnight shelters for homeless people.
But some people still choose not to go to a shelter. So how do those who sleep outside manage in the extreme cold?
When the morning sun hits the east bank of the Willamette River in Portland, it's time for Mark Seaton and David Somers to pack up camp.
The two homeless men spent the night outside, wrapped in layers and blankets. A sheen of white frost is just starting to melt on their sleeping bags.
You have to be well-prepared for these temperatures, says David Somers.
Somers explained, "We just have tarps that we kind of make into a hut. And then we also have plenty of blankets because it does get cold. And some people they kind of freeze out here."
This week, nighttime temperatures have dipped into the low 20s.
"It's in an area that I call danger cold," says Somers' best friend and camping partner, Mark Seaton.
Seaton said, "We can watch out for each other out here. I used to always carry extra blankets, sleeping bags, cause I always find people who didn't have enough or who didn't have any at all. You just have to bundle up, stay active, drink hot liquids if you can get them."
The two men camp together every night. Seaton has been homeless for thirteen years, David Somers for 30 years. They say it's safer to have a buddy out here.
Seaton said, "We just kind of support each other."
Somers added, "We're like a fungus we kind of grow on each other."
The low temperatures this week prompted several churches and community centers to open their doors as emergency shelters. The Union Gospel mission invites people in who don't have a place to sleep.
Stacy Kean is the communications director at the mission.
Kean said, "We really try to help everybody that we can. We don't want anybody stuck outside - that could be a life or death situation with temperatures this low."
The Union Gospel shelter has room for 60, and there are several other facilities around the city that are prepared to make sure people don't have to sleep in the cold.
But these two men say they prefer to take the risk.
Somers said, "I do not like to stay in shelters because of bed bugs and people snoring and every little thing keeps me awake."
They've got a dog named Goldie -- a small, blonde terrier wearing a fleece vest. The dog helps them stay warm at night, too.
About a half mile away, a young woman pops her head out of a large, brown tent. The only name she'll give is "Purple"-- fitting, because of the lilac streaks in her dreadlocks.
Twenty-year-old "Purple" spent the night under the Ross Island Bridge with her boyfriend. They also have a dog. She says the temperatures make it that much harder to be homeless.
"Purple" said, "It's slow, trying to get moving. Once you get moving it's easier. But waking up and it's that chill. Nights are harder, nights are harder than days. There hasn't been any snow yet but there probably will be."
When it gets cold, she says she panhandles for cash to buy propane. A small four dollar tank can heat the tent for 45 minutes, she says.
"It's definitely not easy out here in the winter. In the summer, it's all right cause it's usually not raining. But when your stuff gets wet, and then it's cold on top of that, hypothermia is something to worry about," she said.
She says she wears two coats and lots of layers to stay warm. But she'd like some mittens.
Purple said, "Cause they are better than gloves cause they keep your fingers together and more heat."
Purple also says she'd rather brave it on the streets than go to a shelter. She's worried about lice, and says she's been turned down because of her dog.
Back on the Springwater Trail, Dave Somers says that even though it's hard in the cold, the clear nights are beautiful.
Somers said, "This is God's territory. That's what I like. I like to lay back at night and watch the stars."
But he doesn't recommend life on the streets.
Somers said, "If you guys out there decide to go out on your own and live outside -- don't. Just stay indoors. It's rough out here and it's getting rougher all the time."
The forecast predicts temperatures below freezing in the Willamette Valley through the weekend.
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This story originally appeared on Oregon Public Broadcasting.