Gov. Andrew Cuomo demanded New Yorkers put down their e-cigarettes and other vaping devices Monday after federal health authorities reported an outbreak of mysterious illnesses tied to the popular devices left hundreds hospitalized across the country.

“This is a frightening public health phenomenon,” Cuomo said. “Common sense says that if you don’t know what you are smoking — don’t smoke it.”

The three-term pol made the remarks as he sat in front of an all-caps sign that read, “Vaping can expose you to toxic chemicals and kill you!” and laid out a new plan to more tightly regulate vaping products sold in New York state.

State regulators will require bodegas and other stores that sell vaping devices and cartridges post warning signs identical to the one at Cuomo’s Midtown press conference.

Cuomo also said the state Health Department has launched a probe into three companies that provide commonly found ingredients in popular vaping cartridges that contain marijuana ingredients, like THC.

Those cartridges remain illegal in New York, but can be purchased in other states.

The New York state probe is in addition to the federal review of nicotine vaping products.

The Centers for Disease Control reported Friday it is probing 450 cases of across 33 states that experts believe are related to vaping. So far, four people have died, including confirmed cases in Indiana, Illinois and Oregon, officials said.

“There is clearly an epidemic that begs for an urgent response,” wrote Harvard’s Dr. David Christiani in an editorial published Friday in The New England Journal of Medicine.

And on Monday, the Food and Drug Administration accused Juul Labs of violating US rules against marketing to teens by telling a group of New York high school kids that its wildly popular e-cigarettes were “totally safe.”

Additionally, Cuomo called for lawmakers to consider a ban on flavored ‘vaping’ products, which critics have claimed are targeted at young consumers.

The New York City Council is debating similar legislation, which was introduced in January. Health advocates hope it will pass by the end of the year.

One of the biggest vaping companies, Juul, did not directly comment on the crisis but said it was cooperating with federal authorities.

“We appreciate the work of the CDC, FDA and other public health authorities and are confident that they will get to the bottom of this issue,” said a spokesman.