Alright parents, here's one to watch out for. There's a mysterious respiratory illness that has affected more than 900 children and teenagers in Colorado just in the past month — some even have to be put in intensive care.

KCNC: "The name is human enterovirus 68... We've not seen it in Denver previously."

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"What doctor Meyappan is seeing is how quickly this virus becomes life-threatening especially in kids with even mild asthma."

HLN: "Doctors think a virus related to one of those that causes the common cold is creating the outbreak."

What's troubling about this virus is it starts out with cold-like symptoms including fever, sneezing, coughing and body aches — making it difficult to properly diagnose until more serious symptoms show up.

KMGH: "To go from a cold to being probably minutes away from death, that's kind of scary."

That was the father of Will Cornejo, a teen with asthma who contracted the virus.

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Will's Mother via KRDO: "He just passed out, had his eyes rolled back in his head."

And although Colorado is one of the states experiencing the most severe outbreaks — the rest of the U.S. isn't in the clear. Just like the common cold,  enterovirus 68 seems to spread easily.

CNN: "Health officials in 10 other states from North Carolina to Oklahoma have also reported suspected outbreaks."

Al Jazeera: "Some states are reporting seventy new cases a day. Kansas, Illinois, Ohio and Indiana are among them but Colorado and Missouri have been hit the hardest."

Because viruses are not treatable with antibiotics, doctors have been giving patients steroids and medication to help improve breathing — as respiratory problems seem to be the most threatening symptom. But the majority of the emphasis is being put on prevention.

That includes washing your hands, disinfecting items that are touched often and avoiding touching your face,  especially your eyes and nose.

Fortunately, there are no reports of any deaths from this outbreak.

This video includes images from Getty Images and Neil Mclntosh / CC By 2.0.