(AP) — U.S. researchers are about to test a way to thwart one of chemotherapy’s most despised side effects — to see if giving the scalp a deep chill can prevent hair loss.

The idea: Cooling the scalp during chemo slows blood flow, making it harder for cancer-fighting drugs to reach and harm hair follicles.

The approach is widely used in Europe and Canada, where several types of so-called cold caps are sold. But the Food and Drug Administration hasn’t approved their use in this country.

The new study asks if it’s time for that to change. This summer, researchers will begin recruiting 110 breast cancer patients to strap on the DigniCap during their chemo sessions. Photos of their hair will show how well the cap works.