GRAPEVINE -- It is a mystery.
The Grapevine Fire Department and Baylor Regional Medical Center at Grapevine haven't determined what made several staff members sick Thursday.
Around 8:30 a.m., a couple of staff members complained of feeling dizzy and nauseous.
Baylor called in the fire department. They checked it out and found nothing.
A few hours later more staff members felt sick, so the fire department went back out. They did some field testing, but they didn't detect anything.
They ran multiple tests and determined it wasn't anything airborne.
Baylor moved 34 patients from the third floor to another area of the hospital as a precaution.
All the staff members appeared to be okay as of Thursday afternoon.
Baylor is still investigating the cause.