It’s hot out there. As we approach summer, you’re going to need plenty of water to stay hydrated and maybe the occasional ice cream to cool down with a sweet treat. Unfortunately, there’s always someone ready to take advantage when conditions get rough, and sweet, innocent ice cream is no exception.

According to reporting from The Guardian, Japanese authorities have raided six of the country’s largest ice cream manufacturers over allegations that they secretly coordinated price increases, potentially violating the nation’s antimonopoly laws.

The companies under investigation are Akagi Nyugyo, Ezaki Glico, Lotte, Meiji, Morinaga Milk Industry, and Morinaga & Co., basically every company that dominates the Japanese ice cream market. Investigators from the Japan Fair Trade Commission suspect that executives at the companies spent years communicating via email and in secret meetings to coordinate when and by how much they would raise prices.

Authorities think the companies may have used rising food costs as a cover to jack up prices beyond what inflation would justify.

All this is happening as Japan is heading into what will no doubt be another brutally hot summer. It’s gotten so hot over there that earlier this year, officials introduced a new word used just to describe how punishingly hot it’s been getting in recent years, specifically to be used when temperatures exceed 40 degrees Celsius: “kokusho,” or “cruelly hot.”

Meanwhile, Japan’s ice cream market hit a record ¥663 billion, or roughly $4 billion US, driven by fervent demand for cold ice cream, no doubt fueled by increasingly extreme temperatures that seem to break new records every summer. All six companies say they are cooperating fully with authorities.

No formal findings have been announced, and the probe remains ongoing.