Stanley issued a recall of 2.6 million of its stainless steel cups on Thursday because of a possible burn hazard, injuring 38 people.

The recall affects all Stanley Switchback and Trigger Action cups sold in the United States between June 2016 and this month, the Consumer Product Safety Commission said in a news release. The Switchback cups were sold in 12 ounces and 16 ounces. options, while the Trigger Action cups were sold in 12, 16, or 20 ounces. Options. Both cup models were sold in different colors and feature the Stanley logo on the front and bottom of the cup.

CPSC also offered a list of specific product identification numbers printed on the bottom of all recalled cups.

For the Switchback cups, the PINs are 20-1437 for the 12-ounce model; and 20-01436 and 20-02211 for the 16-ounce model.

For the Trigger Action cups, the PINs are 20-02033, 20-02779, and 20-02825 for the 12-ounce cup; 20-02030, 20-02745 and 20-02957 for the 16 oz; and 20-02034 and 20-02746 for the 20 ounce model.

The Stanley cups are being recalled because the threads on the lid can shrink when subjected to heat and torque, causing the lid to come loose during use, posing a burn hazard to consumers, according to the CPSC. This defect resulted in 91 reports worldwide, including 16 in the United States, of cup lids coming off during use, resulting in 38 burns, including two in the United States. According to the CPSC, 11 of those injuries required medical attention.

Any consumers who own any of the recalled Stanley cups should “immediately discontinue use” and contact Stanley for a free replacement lid with shipping covered, according to the CPSC.

Stanley also “voluntarily” posted the recall on his social media accounts.

“At Stanley 1913, we are committed to continuous improvement and focused on creating quality products that are built for life,” the company wrote in an Instagram post.

Consumers can also contact Stanley by phone at toll-free 866-792-5445, Monday through Friday, 8 a.m. to 5 p.m. Eastern, or online at the dedicated Stanley Cup Recall website.