Why people suck ice chips during certain chemo infusions

This page is for people getting chemotherapy who have heard about sucking on ice chips during an infusion. It explains what oral cryotherapy is, when NCI says it may help, and why it does not suit everyone.

Somebody is sitting with a cup of crushed ice, working through it steadily while their drip runs. It looks like a comfort measure. It is not only that.

The method is called oral cryotherapy (cooling the mouth). The goal is to cool the lining of the mouth while a certain drug flows through the body, to reduce the damage that drug does there.

This is a targeted technique for specific regimens. It is not general advice for everyone on chemotherapy.

The problem is mucositis. NCI describes oral mucositis as inflammation of the lining of the mouth. It usually looks like red, burn-like or ulcer-like sores. NCI says it may cause pain, infection, bleeding in people getting chemotherapy, and trouble breathing and eating.

The National Cancer Institute's patient summary on oral complications describes the practice in two settings.

For one specific drug: "Swishing ice chips in the mouth for 30 minutes, beginning 5 minutes before patients receive fluorouracil, may help prevent mucositis."

And for transplant conditioning (the treatment given before a stem cell transplant): holding ice chips in the mouth during high-dose chemotherapy may help prevent mouth sores in stem cell transplant patients.

Two things stand out. NCI names the drug and the setting, rather than chemotherapy in general. And it says may help, which honestly reflects how strong the evidence is.

NCI's professional-level summary lists cryotherapy for patients getting bolus fluorouracil chemotherapy (given all at once rather than slowly) among its topical management options for mucositis. This makes it something to discuss with your team. It is not a proven step to insist on.

NCI names fluorouracil and high-dose chemotherapy before stem cell transplant. It does not describe ice as right for every drug. Some drugs are known to cause cold-triggered nerve symptoms, and our page on oxaliplatin cold sensitivity covers that. We could not confirm that point in an NCI page we opened, so ask your team about your own drugs.

So the rule is simple, and it matters. Do not start ice in your mouth during an infusion just because you read about it, or saw someone else doing it. Ask first whether it applies to your drugs.

If you are having a regimen where mouth sores are expected, this is a fair and specific question for your nurse or oncologist:

• Is oral cryotherapy something you use for my regimen?
• If so, when should I start relative to the drug, and for how long?
• Is there any reason ice would not suit my drugs?
• What else does your unit recommend for mouth care during treatment?

Many infusion units already have a set routine and will simply hand you a cup. Others will not use it for your drugs, and will tell you why.

Ice chips, where they fit, are one small piece of protecting your mouth through treatment. They do not replace the rest of your mouth care. Ask your team what they advise, and report soreness early rather than waiting to see if it settles.

NCI stresses that people should talk with their doctors about mouth pain. If eating, drinking or sleeping is being affected, tell your team. If you have trouble breathing, call 911.

NCI, Oral Complications of Chemotherapy and Head/Neck Radiation (PDQ, patient version, last reviewed 2024-10-15) and the health professional version (cancer.gov).