The U.S. Pentagon has granted the Department of Homeland Security permission to test a military-grade heat ray, known as the Active Denial System, for possible deployment along the U.S.–Mexico border, according to a memo obtained by CNN.

Defense Secretary Pete Hegseth signed the September memo, allowing DHS to borrow the device for seven months and develop tactics for its potential use in border operations.

The ADS emits invisible electromagnetic waves that produce an intense burning feeling on skin without touching the person.

How the Heat Ray Works

Developed by the U.S. military, the non-lethal system can fire an invisible beam of electromagnetic energy a little over half a mile.

Military officials say the beam creates a sensation comparable to opening a hot oven, lasting 10 to 15 minutes and prompting a strong desire to move away.

Its purpose is to disperse crowds without resorting to conventional weapons.

Pentagon Approves Testing

The Pentagon authorized DHS to borrow one Active Denial System for seven months, starting in September 2026.

Under the agreement, DHS will operate the device and devise procedures for possible use, while Pentagon staff will not handle the system.

The memo does not reveal the testing location or future deployment plans.

DHS may ask for an extension beyond the initial period if further testing or deployment is needed.

Previous Deployment Plans

CNN reports that U.S. Customs and Border Protection officials have previously looked at using the weapon to control crowds and deter unauthorized crossings.

In 2018, officials discussed employing the system against migrants, but then-Homeland Security Secretary Kirstjen Nielsen rejected the idea.

The device was also considered during protests after George Floyd's killing in 2020.

The military once deployed the system in Afghanistan but never fired it in combat.

Safety and Legal Concerns

The proposal has sparked worries about safety, legality and risks to migrants.

Former border officials warned that people fleeing the heat ray might run into hazardous areas, such as rivers, raising drowning risks.

Questions have also been raised about whether the weapon could be aimed at individuals who have not yet entered U.S. territory.

Some Border Patrol agents have expressed doubt about the need for the technology, noting fewer crossings and higher staffing levels.

A CBP spokesperson told CNN the agency continues to assess new technologies to improve its operational capabilities.

At present, DHS has permission to test the system, but officials have not confirmed any deployment at the U.S.–Mexico border.