Take your pick: 101 or 102 degrees.

That's what forecasters are predicting for the Modesto area through Saturday.

It would mark the second big heat wave of the summer. Previously triple-digit temperatures came on three days in late June, according to records kept by the Modesto Irrigation District.

As the temperature climbs from a predicted 101 today to 102 on Thursday, air quality is expected to go down -- so much so that the San Joaquin County Air Pollution Control District already has declared Thursday a Spare the Air day in Merced and Stanislaus counties.

People are asked to curtail driving, skip yard work with gasoline-powered equipment and forgo lighter fluid for barbecues -- all to lessen the amount of pollutants going into the air, thereby making it easier for people to breathe.

Breathing difficulties are just one problem caused by hot days.

Medical experts warn that children and the elderly should be closely monitored for heat exhaustion and dehydration.

Symptoms can include "confusion, fatigue, heavy sweating followed by dry hot skin, weakness, fainting, loss of consciousness, and -- rarely -- death," said Dr. Grant Dawson, medical director at the Stanislaus County urgent care center in Modesto.

Dawson advised people to wear loose-fitting clothes and wide-brimmed hats, to stay out of the sun, eat small meals, abstain from alcohol and other fluids like iced tea and Gatorade, and -- most important -- to drink plenty of water.

"The big thing is water," he said. "Nothing beats water."

Dawson also cautioned against leaving children in cars.

"Even with windows rolled down, the temperature can quickly exceed 150 degrees," he said. "Every year we have parents say, 'Well, we rolled the windows down -- we thought it would be OK.' It's not. Particularly for babies and seniors."

Children who have been left in hot cars often suffer body temperatures exceeding 104 degrees, he said.

"Their bodies are limp, they are unresponsive," Dawson said.

In less severe cases, children experience muscle cramps, shallow breathing, low oxygen levels and confusion.

"It's not a pretty picture," he said.

The Stanislaus County Chapter of the Society for the Prevention of Cruelty to Animals asked people to be mindful of their pets.

Pet owners should never leave animals in parked cars, said Kelly Kellett, an SPCA volunteer.

"Children die in cars," she said, "and so can animals."

Kellett said that on days when temperatures exceed 100 degrees, animals should be brought inside so they can benefit from air conditioning.

Leave pets outside only if there is plenty of shade and water, Kellett said.

She added that pets suffering from heat stroke will be listless and dehydrated.

This week's spate of 101- and 102-degree days would not be record-breaking, said Maree Hawkins, a spokeswoman for the Modesto Irrigation District, which has kept records since 1939.

She said the hottest July day on record was in 1972, when it reached 111 degrees on the 14th.

On average, temperatures in Modesto reach triple digits three times a year in June, 5 1/2 times in July and four times in August, she said.

The hottest temperature ever recorded in Modesto was 112 degrees, on June 15, 1961.

Bee staff writer Chris Togneri can be reached at 578-2311 or ctogneri@modbee.com.

Reprinted by permission of Modesto Bee.