Hyperbaric Oxygen Therapy for Frostbite: What the Evidence Shows

Important: Hyperbaric oxygen therapy is not FDA-approved for frostbite. Using it for cold injury is investigational, supported only by case reports and small series. Insurance will not cover HBOT for this purpose, so all costs are out-of-pocket.

Frostbite of the fingers or toes raises one question above all others. Can the tissue be saved. The people searching HBOT for frostbite are often the patient, a climbing partner, or a family member trying to weigh every option in the hours and days after a cold injury. The honest summary is that HBOT for frostbite sits at the edge of the evidence. A small number of case reports describe limbs that recovered after treatment, but no randomized trial has tested it.

What Frostbite Does to Tissue

Frostbite happens when skin and the tissue beneath it freeze. Ice crystals form, small blood vessels are injured, and circulation to the area shuts down. Fingers, toes, ears, the nose, and the cheeks are the usual sites because they lose heat fastest.

The damage comes in stages. The freezing itself kills some cells outright. Then, as the area is rewarmed, a second wave of injury follows. Blood returning to the thawed tissue triggers inflammation, clotting in the small vessels, and swelling that can choke off the circulation the tissue needs to survive. This reperfusion phase is where much of the tissue loss actually occurs, and it is the part that treatments like vasodilator drugs and HBOT are aimed at. Deep frostbite is graded by how far the injury reaches. The deepest grades extend to bone and joint and carry the highest amputation risk.

Why Researchers Look at HBOT for Frostbite

The rationale overlaps with how HBOT is used in injuries the FDA has cleared it for, including crush injuries and certain problem wounds. Breathing pure oxygen under pressure dissolves far more oxygen into the blood plasma than normal, and that dissolved oxygen can reach tissue that damaged or clamped-down vessels are no longer supplying well. Researchers studying frostbite have proposed that the extra oxygen may support marginally viable tissue at the edge of the injury and blunt part of the reperfusion damage. For a plain explanation of the mechanism, see how HBOT works.

That logic is borrowed from conditions where the evidence is stronger. On its own it does not prove HBOT works for frostbite. The Wilderness Medical Society makes the point directly. Oxygen under pressure raises oxygen levels in the blood, but the oxygen still has to be carried to the distal tissue, and in severe frostbite that blood supply may already be gone.

What the Research Shows (and Doesn’t)

There is no randomized controlled trial of HBOT for frostbite. The evidence is case reports and small series, which means there is no control group to separate what HBOT did from what rewarming, time, and other treatments did.

Finderle and Cankar (2002) described a patient treated more than two weeks after a frostbite injury and measured improved nutritive skin blood flow in the affected area after HBOT (PMID: 11952063). Kemper and colleagues (2014) reported two frostbitten toes treated with delayed HBOT that healed without amputation (PMID: 24649719). Reports like these are encouraging to read, but single cases cannot tell you how often the same approach fails, because failures are far less likely to be written up.

The most informative study to date is not a trial either. Magnan and colleagues (2021) compared 28 patients with grade 3 or 4 frostbite treated with HBOT plus the drug iloprost against 30 earlier patients treated with iloprost alone (PMID: 34833502). The combined group preserved more tissue, a mean of roughly 13 segments per patient versus 6. Because the comparison group came from an earlier time period rather than random assignment, that result points in a direction rather than settling the question.

The Wilderness Medical Society’s 2024 frostbite guidelines weigh all of this and conclude that HBOT cannot be recommended due to insufficient evidence, while noting that the retrospective and case-control data show improvement in some wounds (McIntosh et al., 2024).

The Approved Treatment for Severe Frostbite Is a Drug

In February 2024 the FDA approved iloprost, sold as Aurlumyn, as the first medication for severe frostbite in adults, to lower the risk of finger or toe amputation. Iloprost is a vasodilator that opens blood vessels and reduces clotting, and it is given soon after rewarming. HBOT was not part of that approval and remains off-label for frostbite.

This distinction matters for anyone reading clinic marketing. A facility may offer HBOT alongside other care, but HBOT itself does not carry FDA clearance for frostbite, and the studies that pair it with iloprost cannot cleanly separate the contribution of each treatment.

If Frostbite Is Happening Now

Frostbite is time-sensitive, and the early steps are handled in an emergency setting, not a hyperbaric clinic. Rapid rewarming, pain control, imaging to assess tissue viability, and decisions about clot-busting or vasodilator drugs all happen in the first hours to days. Those choices belong to an emergency department and a wound or burn team.

If HBOT comes up at all, it would be as an add-on to that care rather than a replacement for it, and the case reports that exist describe it used in a hospital under specialist supervision. Ask your care team whether it has any role in your specific injury and timing. Do not delay emergency treatment to arrange HBOT, and do not assume a private clinic course will save tissue that the treating team has already assessed. No one can promise a frostbitten digit will be saved.

For how oxygen-based therapy is used in injuries where the evidence is established, the pages on crush injuries and non-healing wounds describe FDA-cleared uses that share some of the same biology.

Frequently Asked Questions

Is HBOT FDA-approved for frostbite? No. HBOT is not FDA-approved or cleared for frostbite. Its use for cold injury is investigational and rests on case reports and small series.

Will insurance pay for HBOT for frostbite? No. Because frostbite is not an approved indication, insurance will not cover HBOT for it. Costs are out-of-pocket.

Has HBOT been shown to save frostbitten fingers or toes? Individual case reports describe digits that healed after HBOT, and one study with a historical control group found more tissue preserved when HBOT was added to iloprost. None of this is a randomized trial, so it cannot establish how reliably HBOT preserves tissue.

What treatment for severe frostbite does have FDA approval? Iloprost (Aurlumyn) was approved in February 2024 as the first medication for severe frostbite in adults, to reduce amputation risk. It is a drug given under medical supervision, not HBOT.

References

Finderle, Z. and Cankar, K. (2002). Delayed treatment of frostbite injury with hyperbaric oxygen therapy: a case report. Aviation, Space, and Environmental Medicine. PMID: 11952063. https://pubmed.ncbi.nlm.nih.gov/11952063/

Kemper, T.C.P.M. et al. (2014). Frostbite of both first digits of the foot treated with delayed hyperbaric oxygen: a case report and review of literature. Undersea & Hyperbaric Medicine. PMID: 24649719. https://pubmed.ncbi.nlm.nih.gov/24649719/

Magnan, M.A. et al. (2021). Hyperbaric oxygen therapy with iloprost improves digit salvage in severe frostbite compared to iloprost alone. Medicina (Kaunas). PMID: 34833502. https://pubmed.ncbi.nlm.nih.gov/34833502/

McIntosh, S.E. et al. (2024). Wilderness Medical Society Clinical Practice Guidelines for the Prevention and Treatment of Frostbite: 2024 Update. Wilderness & Environmental Medicine, 35(2), 183-197.

U.S. Food and Drug Administration (2024). FDA Approves First Medication to Treat Severe Frostbite. https://www.fda.gov/news-events/press-announcements/fda-approves-first-medication-treat-severe-frostbite

See all conditions on the conditions hub. For FDA-cleared uses that rely on the same oxygen-delivery biology, read about crush injuries and non-healing wounds. To understand the mechanism in plain terms, see how HBOT works.

Medical Disclaimer: This page is for informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before pursuing any medical treatment.