When Stella Liebeck sued McDonald's because their coffee burned her, it spawned a thousand jokes. It's likely even you told one. It's only when you dive into the details that you quickly realize it was not a frivolous lawsuit. The 88 °C coffee caused third-degree burns in her pelvic region, resulting in two years of medical treatment. I recommend the documentary Hot Coffee for more about Liebeck v. McDonald's Restaurants.
Today, your coffee likely has a warning on the label that it's hot. That may seem redundant to you, but it's nothing like the sign I saw on Saturday.
During my daughter's soccer practice, I used the facilities and found this sign above the urinal. It reads "Please flush after using. Thank you".
I can only imagine what led to the decision to print and post this sign.