Four of Oregon’s 13 prison facilities are not equipped with central air conditioning heading into this weekend’s potentially historic heat wave, where temperatures are projected to climb as high as 115 degrees.

“The agency has been monitoring the weather and is making preparations for this weekend’s heat wave. [Department of Corrections] makes every attempt to keep the adults in our custody and employees comfortable,” says agency spokeswoman Betty Bernt. “Each of our institutions has plans for inclement weather; modifications vary by location based on infrastructure and other dynamics.”

The facilities without a central cooling system are Oregon State Penitentiary in Salem, which is the state’s oldest prison, built in the mid-1850s, and the only maximum-security facility in Oregon; Santiam Correction Institution, also in Salem; Shutter Creek Correctional Institution in North Bend; and South Fork Forest Camp in Tillamook.

The latter two facilities are both near the Oregon Coast, where temperatures aren’t expected to hit triple digits.

But Oregon State Penitentiary and Santiam Correction Institution are located in the Central Willamette Valley, where temperatures might reach a high of 115 degrees on Sunday.

For facilities without air conditioning, Bernt says, DOC plans to open windows and use fans and swamp coolers, which are ideal for dry environments because they evaporate water into the air in order to cool (they can have the opposite of a cooling effect in humid climates).

Other precautions include providing ice water to adults in custody and staff, shutting down outdoor recreation, and limiting transportation of adults in custody between facilities, according to Bernt.

At this time, Bernt says, DOC does not have plans to transport adults in custody from facilities without air conditioning to ones that do: “No transports are anticipated to be made due to the heat exclusively.”

Transports are a strategy the department tried last September as wildfires ravaged the state. It resulted in dozens of reports of COVID-19 transmissions, allegations of food tampering, and fights between rival gangs that are typically separated to prevent such incidents.

The heat wave is likely to be more manageable inside of the two Portland-area jails—the Multnomah County Detention Center located downtown, and the Inverness Jail in Northeast Portland—which are equipped with modern cooling systems, according to Multnomah County Sheriff’s Office spokesman Chris Liedle.

“Both facilities are built to withstand extreme heat and cold,” Liedle says. “They are equipped with modern HVAC systems and back up generators, in case of power outages.”