Amazon Heated Insoles Lawsuit Alleges Foot Warmer Burst Into Flames Inside Boot

Lawsuit adds to a growing wave of claims accusing Amazon of selling unsafe or defective heated insole products, which can cause devastating injuries if the battery-powered foot warmers fail.

A Colorado woman has filed a product liability lawsuit alleging that heated insoles sold through Amazon burst into flames while she was wearing them, causing severe injuries that required multiple surgeries and long-term medical treatment.

The complaint (PDF) was brought by Jennifer Monnier in the U.S. District Court for the District of Colorado on December 29, naming Amazon.com Inc., Amazon.com Services LLC and Amazon Advertising LLC, along with several Chinese companies accused of manufacturing the defective heated insoles, as defendants.

Heated insoles, also known as foot warmers, are battery-powered inserts designed to fit inside shoes and generate warmth through internal heating elements. Most models offer adjustable temperature settings, which may be controlled by buttons or, in some cases, a mobile app.

While these products have become increasingly popular for cold-weather comfort and circulation support, defective designs or manufacturing flaws can create serious safety hazards, leading attorneys to begin investigating heated insoles lawsuits. In many cases, defective designs increase the risk that lithium-ion batteries used in the products may overheat, ignite or cause severe burn injuries.

According to her lawsuit, Monnier purchased Coowalk-branded heated insoles from Amazon in October 2023 to help manage her Raynaud’s disease, a condition that causes extreme sensitivity to cold. However, instead of functioning safely as advertised, the foot warmers allegedly overheated and ignited inside her boot during normal use.

The incident occurred on February 10, 2024, while Monnier was walking her dogs in Fort Collins, Colorado. Shortly after activating the heated insoles, Monnier states that the device inside her right boot overheated, caught fire and began producing smoke, causing immediate and excruciating pain.

Monnier claims she struggled to remove the lace-up boot as the insole continued to burn, eventually discovering that the device had melted and adhered to her skin. She was transported to a local hospital for emergency treatment and later referred for specialized wound care.

The lawsuit states that Monnier underwent months of medical treatment, including repeated wound debridement procedures, physical therapy, and reconstructive surgery. Monnier further alleges that her injuries ultimately required two skin graft surgeries in 2025, including placement of a bilayer skin graft followed by a split-thickness graft harvested from her thigh.

Monnier says that she continues to suffer from chronic pain, swelling, limited mobility, gait impairment and difficulty wearing normal footwear, with additional medical care expected in the future.

Defective Foot Warmers Sold on Amazon

Monnier alleges that Amazon exercised control over the defective insoles’ sale, storage, delivery and post-sale handling through its Fulfilled by Amazon program.

According to the complaint, the company had prior knowledge of similar safety incidents involving certain kinds of foot warmers overheating and igniting before Monnier was injured, citing reports from other consumers, including at least one incident in December 2023 in which a customer allegedly contacted Amazon from a hospital to warn that these kinds of products pose an urgent fire hazard, and urged their removal.

Despite those warnings, Monnier claims the heated insoles remained available for sale on Amazon’s platform until at least November 2025.

The complaint further alleges that Amazon publicly represents that it monitors products sold on its marketplace for safety hazards, issues warnings to consumers and removes dangerous items when necessary. Monnier indicates she relied on those representations when purchasing the product.

“The Heated Insoles were unreasonably dangerous when they were placed into the stream of commerce in that they were prone to overheating, igniting, and causing burn injuries during normal and foreseeable use.”

— Jennifer Monnier v. Amazon.com Inc. et al

The lawsuit raises claims of strict product liability, negligence, failure to warn and statutory manufacturer liability under Colorado law. Monnier is seeking compensatory damages, punitive damages and other relief.

In a similar claim filed earlier in December, a Kansas woman alleged that Amazon heated insoles exploded and caught fire moments after she inserted them into her work boots, causing severe burn injuries to her feet. That lawsuit contends the rechargeable foot warmers were defective and unreasonably dangerous, igniting during normal use despite being marketed as safe for outdoor wear.

Heated Insole Lawsuits Under Investigation

As a number of burn injuries being linked to defective heated insoles, electric socks and foot warmers continue to be reported, heated insole burn injury lawyers are now investigating claims for individuals nationwide who purchased the products and experienced any of the following:

• Burns to the feet or toes
• Heated insole overheated, ignited or caught fire during normal use
• Emergency medical treatment or hospitalization for burn injuries
• Surgery or skin grafts related to foot burns
• Ongoing pain, scarring or mobility limitations

Heated insole lawsuits seek to hold manufacturers and distributors, such as Amazon, responsible for placing allegedly dangerous products into the marketplace without adequate safety testing or warnings. 

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