The source of the illness has yet to be pinpointed, but doctors say it's entirely possible this is carbon monoxide poisoning.
At least one of the 22 Austin High School students who suddenly became sick was diagnosed and treated for carbon monoxide poisoning.
"They call carbon monoxide the silent killer because it's odorless, tasteless, can't see it," said emergency medicine specialist Dr. Robert Szema with Memorial Hermann Hospital, Memorial City.
Szema says carbon monoxide cuts off oxygen to your body. Your symptoms depend on your level of exposure and can include dizziness, nausea, seizures and even death.
The symptoms are so vague, Szema says it's sometimes hard to tell that you've been exposed to carbon monoxide.
"It sually it happens when you don't have enough ventilation in the area, but it's possible even if you're outdoors if you're in close proximity to a CO source that you will get CO poisoning as well," he explained.
Like some of the students we spoke with last night, patients with carbon monoxide poisoning usually get a hospital blood test that indicates the level of carbon monoxide in their system. Once your levels are low enough, you're discharged and safe to return home.
But, according Szema, that doesn't mean you're out of the woods yet.
"Keep observing, make sure there's someone there with you, no mental status changes and that you're continuing to get better," Szema said.
Those with a higher concentration would be admitted to the hospital and treated with oxygen. Anyone with severely high levels might be placed in a hyperbaric chamber, which puts you under a higher concentration of oxygen.
Experts say the students could have been exposed from standing by buses or generators. We spoke with an assistant chief at the Houston Fire Department who said none of their readings picked up high levels of carbon monoxide when they tested for it.