Thermal, Calif. -

The overnight low temperature Monday night into Tuesday morning in Thermal was a record-low of 21 degrees.

To protect their crops from frost, many farmers in Thermal and Mecca set fire to hay bales around their fields, warming the air around their fruits and vegetables.

The South Coast Air Quality Management District allows farmers to set controlled burns, "necessary to prevent frost," when temperatures are reasonably expected to go below 40 degrees. An AQMD representative says nine areas in Thermal and Mecca notified the agency they would set burns Monday night.

East valley residents noticed.

The fires sent smoke into nearby communities for miles, making it difficult to breath and see, some say.

Oasis Elementary School is surrounded by farms.

"It's a concern because of the school coming in, and the smoke being so condensed here at the site," Oasis Elementary School Principal, Dora Flores said. "We feel that it's a health issue for our students."

Our viewers sent us video and pictures of smoke blanketing east valley farming communities Monday night and Tuesday morning. The health concerns from the smoke caused the Coachella Valley Unified School District to call a public meeting with the South Coast Air Quality Control District at Oasis Elementary Wednesday at 3:30 p.m..

"The teachers are trying to have some preventative measures so that we can make sure that we don't only save the crops," Flores said, "But we also save our students."

We spoke with multiple people off camera who did not want to go on camera because the agriculture industry in the east valley is so important. They say these burns happen every year when temperatures drop below freezing, but this year the smoke has been especially bad, and they say something needs to be done to lessen it.

"When the weather doesn't heat up as fast," Flores says, "Then the smoke just kind of settles."

While farmers are allowed to set the controlled burns, they are not exempt from causing a public nuisance from things such as smell and smoke.

The AQMD says a minimum level of complaints need to be filed before they will investigate. At least six different individuals must report the same incident in a timely manner, an AQMD representative says.

To report an air quality nuisance, call the AQMD's 24-hour hotline at 1-800-CUT-SMOG or 1-800-288-7664.