21 students hospitalized for heat illnesses after bomb-threat evacuation at Carter Middle School, Tennessee

21 students at Carter Middle School in Knox County, Tennessee, were transported to the hospital with heat-related illnesses on September 4, after a reported bomb threat prompted an evacuation to a football field, according to Rural Metro Fire.

The Knox County Sheriff’s Office (KCSO) estimated that students were outside for about 50–55 minutes while a National Weather Service (NWS) Heat Advisory was in effect. Rural Metro said three students were classified as critical when transported; their subsequent medical conditions had not been publicly confirmed as of September 6.

KCSO was notified of the potential threat at approximately 09:56 EDT (13:56 UTC) after a threatening message was discovered on a bathroom wall. School administrators moved students to the football field at approximately 10:25 EDT (14:25 UTC) while KCSO K-9 teams searched the building.

Students were permitted to reenter at approximately 11:27 EDT (15:27 UTC). KCSO separately estimated that they had spent about 50–55 minutes outside.

Several students exhibited signs of heat-related illness after returning to the building, prompting emergency medical personnel to evaluate and treat them, KCSO said.

Rural Metro Fire spokesperson Jeff Bagwell told Spectrum News that 21 students were transported to the hospital, including three classified as critical at the time of transport. Later information about their medical conditions had not been publicly confirmed as of September 6.

Bagwell said some students developed symptoms while they were on the football field and were moved into a nearby field house. Additional students reportedly developed symptoms after returning to the school building.

An NWS Heat Advisory covering Knox County remained in effect until 20:00 EDT on September 4 (00:00 UTC on September 5). The advisory forecast heat index values reaching 41°C (106°F) across the affected area.

FOX Weather reported that the heat index in Knox County was approximately 36°C (96°F) at around 11:20 EDT, near the end of the evacuation. This observed value was lower than the advisory’s forecast maximum for the wider affected area.

NWS warned that high temperatures combined with elevated humidity could cause heat-related illnesses. The agency advised residents to drink fluids, remain in air-conditioned spaces and avoid direct sunlight.

Knox County Schools Superintendent Jon Rysewyk said students were provided with water and shade and that school nurses evaluated students on the field. He said the district would review the incident and consider whether its evacuation procedures should be changed during periods of excessive heat.

School officials notified parents about the evacuation and subsequently informed them that the building had been cleared, according to local reporting.

KCSO said juvenile detectives continued investigating the circumstances surrounding the threatening message.