If you thought Monday was too hot, you're going to hate Wednesday.

The Valley's first true heat wave of summer is upon us and temperatures are expected to stay in the triple-digits through the end of the week, forecasters say.

Fresno is expected to hit a high of 109 on Wednesday and 106 on Thursday. Wednesday's high will approach the record for the day.

"We flirted with triple-digits earlier this summer, but this is our first extended stretch of triple-digit heat," said Jim Bagnall, a meteorologist with the National Weather Service in Hanford.

Bagnall said the near-record heat shouldn't come as a surprise.

"The heat is typical for the time of year, although on Wednesday, our predicted high is 109, and that is near the record high of 110" set in 1961, Bagnall said.

And it won't get much cooler when the sun goes down. Overnight lows are forecast to stay in the low to mid-70s.

By early next week, high temperatures are expected to fall into the upper 90s for a few days before spiking back to the century mark, Bagnall said.

"With the standard pattern of hot weather, then a period of brief relief, we could be looking for another heat wave," Bagnall said.

In response to the scorching temperatures, cooling centers in Fresno opened their doors Monday and will remain open through Friday from noon to 8 p.m., said Fresno's parks spokeswoman Heather Heinks.

In most Valley communities, cooling centers open their doors on days when temperatures hit 105 degrees.

"There is no need to suffer. The community needs to realize they have options," Heinks said. "There are places to cool off -- from community centers to libraries to businesses."

Also because of the heat, Fresno fire officials are urging extra care when transporting children and pets. Residents also can protect themselves by recognizing the signs of heat exhaustion, limiting outdoor exercise and drinking plenty of water.

With the heat comes "very, very high" fire danger, said Dana Dierkes, spokeswoman for the Sequoia and Kings Canyon National Parks.

Cal Fire, which is the first responder for much of the foothills, has added more personnel and equipment because of the heat and expected wind, Capt. Aldo Gonzalez said.

No relief

Temperatures are projected to remain above century mark for next seven days:

108

Today

109

Wednesday

106

Thursday

103

Friday

101

Saturday

101

Sunday

106

Monday

Cooling centers

Fresno: Frank H. Ball Community Center, Pinedale Neighborhood Center, Mosqueda Community Center and Ted C. Wills Community Center open through Friday from noon to 8 p.m.

Clovis: Using Sierra Vista Mall as its cooling center site.

Hanford: Coe Park Hall, 543 S. Douty St., expected to open from 1 to 8 p.m. today and Wednesday

Tulare: Senior Community Center, 201 N. F St., open through Friday from 10 a.m. to 5 p.m.

Visalia: Visalia Transit Center, 400 E. Oak Ave., open today through Thursday from 10 a.m. to 10 p.m.

Sources: City spokespeople

Heat wave safety tips

Slow down: Strenuous activities should be reduced, eliminated or rescheduled to the coolest time of the day.

Dress for summer: Lightweight, light-colored clothing reflects heat and sunlight, and helps your body maintain normal temperatures.

Put less fuel on your inner fires: Foods (such as proteins) that increase metabolic heat production also increase water loss.

Drink plenty of water or other non-alcohol fluids: Your body needs water to keep cool. Drink plenty of fluids, even if you don't feel thirsty.

Spend more time in air-conditioned places: Air conditioning in homes and other buildings markedly reduces danger from the heat.

Don't get too much sun: Sunburn makes the job of heat dissipation that much more difficult.

Source: National Weather Service