Famously, well-meaning tourists occasionally try to pet buffalo at Yellowstone National Park. The results are not good.
But another dangerous behavior might not immediately be obvious. In July, a video went viral of an older man taking a drink of water from a thermal hot spring at Yellowstone. Turns out that is an awful idea.
According to the Yellowstone Park safety page, drinking untreated thermal water is unsafe for humans because the springs have high levels of mercury, arsenic, and microorganisms like Naegleria, the brain eating amoeba.
Plus, hot springs can be boiling hot and just below the surface is sulfuric acid. About 20 people have died from burns in the hot springs. In 2016, a 23-year-old man died after falling in a spring. His body was dissolved in 24-hours and could not be recovered.