The incident happened during lunchtime, Spring ISD said in a release. The school nurse examined both students and recommended they get further medical attention.
A student sent ABC13 a video that shows more urgency than the district's description. The students are seen lying on the ground and appear to be unconscious. A nurse and school staff are seen assisting them.
An ambulance was called to the school and the students were taken to Houston Northwest Medical Center.
"The Spring ISD Police Department is currently investigating this incident, as the safety of our students is our top priority," the district said, adding that classes continued without interruption.
The school district did not say what caused the students to get sick but said they are looking into what happened, and whether it was the result of an overdose. The students' conditions are unknown.
Parents started posting on social media as the video was circulating. Two mothers told ABC13 they contacted their children immediately and warned them never to ingest anything from an unknown source.
For more on this story, follow Jessica Willey on Facebook, Twitter and Instagram.