Medford's all-time record high temperature, held for 71 years, could get a run for its money Wednesday.

The mercury is forecast to peak at 114 degrees — 1 degree below the record, set July 20, 1946.

The National Weather Service issued an excessive heat warning through 8 p.m. Friday for a sizable chunk of Oregon, with temperatures anywhere from 100 to 115 degrees possible, and dropping only to the mid-70s overnight.

"The nighttime lows are a factor in whether or not to issue an extensive heat warning," said meteorologist Michelle Cohen in the weather service's Medford office. "If we cool off enough at night, we wouldn’t issue it."

Medford's already set one record this week — 108 on Tuesday, four degrees hotter than the last record for Aug. 1, set in 2015. The high on Monday was 104, five degrees off the temperature record for July 31 of 109, set in 2015.

Officials advise residents without air conditioning to find places where they can keep cool during the day, such as Rogue Valley Mall and county libraries. In Ashland, a cooling center will be open to anyone from 12:30 to 5:30 p.m. Wednesday and Thursday at Temple Emek Shalom, 1800 E. Main St., according to the city's website.

The Salvation Army will hand out cold bottles of water at 304 Beatty St. from 8 a.m. to noon and 1 to 5 p.m. Wednesday, according to Maj. Jason Koenig of the organization's Medford Citadel Corps. It also will hand out bottled water at 922 N. Central Ave., where those who qualify based on income can also receive a free fan. Interested parties should bring a photo ID and proof they live in Jackson County. The fan is theirs to keep.

More than 100 fans have been given out over the last two months, Koenig said.

"I'm suspecting after this week we'll be going to get another 50," he said.

Ways to beat the heat

Here are some tips for protecting yourself and keeping your home as cool as possible, many provided by Pacific Power:

• Stay hydrated. One easy rule of thumb is to divide your weight in half, then drink that many ounces of water daily, much more if you’re exercising in the heat.

• Limit exposure to the sun; wear sunscreen and hats. 

• Limit use of heat-producing appliances, such as ovens and dryers, to early morning and late evening. Switch off devices that generate heat, even small ones such as lamps, computers and televisions, when not in use.

• Set the thermostat at 78 degrees, which will keep the house cool but will also save up to 8 percent on power bills. While away from home, the AC should not be switched off, but raised to 85 degrees instead. That setting allows your air conditioner to use less electricity to cool the house than if the air conditioning had been off all day.

• Use fans to help cool and circulate the air; they use less electricity than an air conditioner when the compressor is engaged.

— Reach reporter Ryan Pfeil at 541-776-4468 or rpfeil@mailtribune.com. Follow him at www.twitter.com/ryanpfeil.