AKRON, Ohio (WJW) — When Akron firefighters were called to an apartment complex for a medical emergency, it didn’t take long for one firefighter to realize they had a bigger problem — carbon monoxide.

Firefighters were called to the Timber Top Apartments & Townhomes on Rocky Brook Dr. just before 10 p.m. Thursday.

As firefighters checked on a 23-year-old man, they said he couldn’t give direct answers to their questions and expressed worry about his birds.

“He was real nervous about them,” Lt. Tim Morrison, Akron Fire Department, said. “He had like 8 or 9 birds in his house and what happened was one of the lieutenants walked over to the birds’ cage and just to say, ‘Oh, everything’s fine,’ and he looked in and he saw four dead birds on the bottom of the cage.”

The firefighter asked the man’s parents how they were feeling and they couldn’t give him a straight answer. That’s when he knew there was a problem.

A carbon monoxide check found high levels of the odorless, colorless gas in the apartment.

Morrison said they ended up evacuating about 20 apartments after high levels of carbon monoxide were found in other units as well.

He said 10 people were transported to local hospitals. The identities of the patients and their conditions were not available early Friday morning.

Morrison said firefighters had to “bust down” the door of another apartment. Inside they found two young children and two adults who were both unconscious.

“It was a great save,” Morrison said.

“It’s pretty amazing Lt. [Cameron] Mack was able to put things together and realize that something wasn’t right,” Morrison said.

“If he wasn’t smart enough to put those things together,” Morrison said. “We’d had a much worse situation going on.”

Once firefighters ventilated the affected apartments, police officers were able to escort other residents to their apartments to retrieve medications and other important things. The American Red Cross was assisting the evacuees with a place to stay until their apartments were safe to return to.

“This shows you how important having a carbon monoxide detector, how important it is, to have that kind of detector in your home,” Morrison said. He also said everyone should have a smoke detector.

According to the Centers for Disease Control and Prevention, every year more than 4,000 people are hospitalized due to carbon monoxide poisoning.

The symptoms can come on quickly, and appear flu-like with headache, dizziness, upset stomach and vomiting. Chest pains and confusion can also be part of the mix. This is problematic if you’re asleep or intoxicated, because the symptoms can creep up on you and have you in trouble before you know it.

While 4,000 people are hospitalized every year for carbon monoxide poisoning, roughly 50,000 will visit the emergency room because of it. An estimated 430 people die from the hazard every year.