The THC-containing oil was in a storage space in the co-op’s commercial kitchen that the store shares with other vendors, according to a statement on the famous Yeti’s website. Ryan told The Washington Post that he knew there was a vendor in the space making THC-infused brownies, but when reports of unexplained reactions to the food started coming in, his mind didn’t jump to THC. Recreational cannabis use is not legal in Wisconsin.

Ryan initially thought some of the vegetable toppings, possibly spinach, were contaminated or spoiled. The fire department even checked the building, located in Stoughton, Wis., for a carbon monoxide leak, concerned that some customers’ symptoms were consistent with CO exposure.

The restaurant eventually linked the incident to THC oil, which was used in 71 orders on October 22 and 23.

Consuming raw cannabis is unlikely to make you sick, said Darin Erickson, associate director of research at the University of Minnesota’s Cannabis Research Center, because the compounds in it are activated during cooking or smoking. People who make edibles infuse cannabis into some kind of fat — in this case, oil — and then use that fat to make other types of food.

The high you get from weed that’s eaten instead of smoked may also be different, Erickson said, because cannabis is metabolized differently in the gut. The timing is different, too. Smokers and vapers feel the effects of cannabis within 5 to 10 minutes, while it can take about an hour for those who use edibles. It can be even faster if one eats high-fat foods.

Fat increases the absorption of cannabinoids, based on preclinical research in rats, said Tory Spindle, associate professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine.

“This increased absorption means that a person would feel stronger effects than if the THC were suspended in something that is not fatty,” he said.

It is the inverse of the relationship between drinking and drinking.

“The interactions between food and cannabis is actually the opposite of food and alcohol,” Spindle said. “Which a lot of people don’t realize.”

Delta-9-THC is the substance in cannabis that gets users hooked. Delta-9 and THC are synonymous, Spindle said.

How long THC stays in users’ systems depends on how often they use the substance and how concentrated the chemical is, but urine tests can generally detect it for about 30 days. Hair tests are even more sensitive and can detect cannabis use for up to 90 days.

The effect that THC has on someone depends on the concentration of the drug and other factors, including the person’s tolerance and age. It’s a mood-altering substance, and some people find it relaxing, while others experience anxiety or panic when they use it, experts said.

“It can have both stimulating and depressing effects,” Erickson said. “Cannabis is kind of weird in that way, not everyone is the same.”

The cannabis plant contains hundreds of different chemicals; the best known cannabinoids are THC and CBD. THC produces a high, while CBD does not, but is believed to have some medicinal qualities. CBD is also legal in most states, while recreational THC is not.

The pizzeria said it is working with authorities to improve storage and security protocols and prevent future problems.

The store was closed Friday to deep clean and get rid of any other potentially contaminated ingredients, Ryan said, and he and his wife are offering financial support to customers who incurred medical bills because of the mistake.