Schools say they could be limiting outdoor actives for their kids. And allergy doctors say they are preparing for a busy day.
The San Joaquin Valley Air Pollution Control District expects the air from San Joaquin to Kern Counties to be unhealthy.
Lorie Cuevas and her children spent Sunday night outdoors. But she knows Monday her kids may have to spend more time indoors, because they have allergies and asthma.
"When it's a bad air day to limit them playing outside in recess and more medication for them," Cuevas said.
Kelly Avants with the Clovis Unified School District said administrators have been watching the air quality closely.
Depending on how bad the air gets Monday, Clovis schools could start limiting how much time students are allowed to spend outdoors.
"We're talking about really prolonged exposure, so a ten minute recess; you're not really going to see a difference for more students. If it goes into an hour for a sports practice outside, obviously that will change," Avants said.
The waiting room inside the allergy institute in Fresno was empty Sunday night. But on Monday, Dr. A.M. Aminian expects to see it fill up, with allergy and asthma patients.
"The cold air by itself it could be aggravating to people with respiratory problems, then the air quality is so poor it can also be aggravating to people with respiratory problems," Dr. Aminian said.
And while the Valley has seen bad air days before Aminain says it is rare to see unhealthy air levels cover so many counties.
"We do see it from time to time here and there, but this would be the extreme," Dr. Aminian said.
For people with serious respiratory problems doctors suggest to stay indoors if possible. And if you have to go outside, limit your time and cover your mouth to keep from breathing in the pollutants.