The call came through just after 8:30 as crews arrived at the Simmons plant No. 2 located on East Main Street.
Officials evacuated the entire plant and crews wore special, protective equipment to investigate.
Other Simmons personnel appeared to complain of similar symptoms, such as difficulty breathing.
A total of 33 people were transported to the hospital, of those 33, five were designated as "immediate" patient status, six were designated as "delayed" patient status and 22 were designated as "precautionary," patient status.
A preliminary investigation shows that a significant amount of dry ice had come in contact with heated water, which created a "plume cloud."
The plume cloud is believed to have depleted oxygen and enhance levels of carbon dioxide.
Emergency officials cleared the building around 11 a.m. and Simmons kept the building closed the business for the rest of the day (Saturday).
The plant sent all workers home and is double checking its systems and fully ventilating the entire structure.