Metro Park Police said they don't want a problem they've noticed in the last few weeks to balloon out of control: concertgoers getting high off of nitrous oxide, otherwise known as laughing gas.

Authorities said they found evidence of people selling balloons filled with nitrous oxide at the Phish Concert back in 2016, and more recently at the Widespread Panic three-day concert at Ascend Amphitheater two weekends ago.

Police said the people selling the gas hid canisters of it among the bushes near the amphitheater, and then they left when police showed up. Police noted the potentially deadly consequences of the gas.

"From what we understand, it gives a brief euphoric high, and sometimes people hallucinate when using it, but it can be deadly when it deprives you of the oxygen," said Sgt. John Wells with Metro Park Police.

Metro Park Police officials said they'll be on the lookout for the unusual Ascend trend, especially during the Phish concert scheduled next month.