Three fire recruits were rushed to Atlanta Medical Center with heat-related illnesses following a training exercise, officials said.

Atlanta Fire Chief Kelvin Cochran told Channel 2's Amy Napier Viteri two of the three recruits were hospitalized after the first day of training on their self-contained breathing apparatus.

During the drills, in which recruits suited up in full turnout gear, the three became dehydrated.

"It is alarming to us. We hear about this happening to football players this time of year with football practice, but never with firefighters," Cochran said. "Two of them were what we called heat exhaustion and one of them entered into the more severe stage of heat stroke."

Cochran said doctors took the recruit with heat stroke off a ventilator on Tuesday.

"He is alert and conscious, has lost none of his faculties; his neurological system is in order", Cochran added.

Fire officials are looking into what caused the heat-related illness. The high temperature Monday was 84 degrees, cooler than previous days for similar training.

Cochran is also looking into whether the recruits were staying hydrated over the weekend leading up to Monday's training.

"Two days without adequate hydration and then arriving on Monday engaging in this type of physical activity could be a contributing factor", he said.

During the drills, supervisors check vital signs and recruits are required to keep hydration logs. Cochran said recruits are not currently required to log hydration over the weekend but the department may begin requiring it.

The Atlanta Fire Department suspended the training until officials determine what caused the illnesses.