OREGON, Ill. (WTVO) — Fall is in the air, and apple orchards are selling cinnamon donuts and apple cider. But health officials are warning that in some cases, drinking unpasteurized apple cider can be harmful.

According to the Ogle County Health Department in Illinois, apple cider — which appears murky and golden colored — does not usually go through a pasteurization, a process involving the application of mild heat, to kill potentially harmful bacteria.

Most people’s bodies can fight off a potential foodborne illness, but others aren’t able to. The health department said, “Highly susceptible populations are the most likely to be affected by unpasteurized apple cider.” Those populations include infants, pregnant people, the elderly and others with weaker immune systems.

The U.S. Food and Drug Administration (FDA) says it has received reports of outbreaks of food poisoning that have been traced to drinking fruit and vegetable juice and cider that has not been pasteurized.

Some apple ciders are pasteurized and others aren’t. Not all unpasteurized ciders will cause problems, either. They are just more likely to contain microorganisms that cause food poisoning than pasteurized alternatives.

You should look to the label when browsing at the store or farm stand for more information.

Juices or ciders that aren’t pasteurized should contain a warning on the label that reads: “WARNING: This product has not been pasteurized and, therefore, may contain harmful bacteria that can cause serious illness in children, the elderly, and persons with weakened immune systems.”

The FDA says if you’re unsure whether the cider has been pasteurized, like if it’s being sold at a farmer’s market or cider mill without clear labels, you should ask the seller.