Cold plunges and saunas used to belong to elite athletes and rich Scandinavian tradition. Now they occupy gym locker rooms, wellness studios, and backyards across the country, and plenty of people with varicose veins are stepping into both.

Cody Laverdiere, DO, is one of the many fans. A board-certified emergency medicine physician and vein specialist, Dr. Laverdiere is the lead physician at Center for Vein Restoration (CVR) in Bend, Oregon. He uses saunas and cold plunges himself, and his patients ask him about them often.

We asked Dr. Laverdiere what heat and cold do to varicose veins, why a sauna can leave swollen legs feeling worse, and the one question to ask yourself before you step in.

What the Research Says About Saunas, Cold Plunges, and Vein Health

Most of the strongest sauna research focuses on the heart and circulation rather than the veins specifically. Dr. Laverdiere explains that vein and lymphatic specialists draw on those cardiovascular findings and apply them to the venous and lymphatic systems.

A sauna puts the body through something close to a workout. A review published in Mayo Clinic Proceedings reports that heart rate during a sauna session can climb from baseline to 120 to 150 beats per minute.

The lymphatic system is the network that drains excess fluid out of the tissues. Dr. Laverdiere says routine sauna use can speed both lymphatic and venous flow.

Heat and cold also set off protective responses inside the body's cells. Heat prompts the body to produce heat shock proteins, which Dr. Laverdiere says activate immune and anti-inflammatory pathways. Cold produces cold shock proteins, which he says push in a similar anti-inflammatory direction.

"The cold plunge is more geared toward anti-inflammatory effects, and the sauna is more geared toward cardiovascular circulation and lymphatic flow," he says.

What a Cold Plunge Does to Varicose Veins

People with varicose veins often notice something striking after an ice bath: their legs feel lighter, and their veins look less pronounced. Dr. Laverdiere says that effect is real. The explanation is vasoconstriction, the tightening of blood vessels.

According to Cleveland Clinic, cold water causes blood vessels to constrict. In the legs, that means veins shrink in diameter.

But the change does not last. Once the body warms back up, the vein returns to its normal size, and blood collects in the same spot again.

"While the symptoms can be relieved for hours afterward, it's really only a temporary effect," he says. "But those hours can really help with daily symptom management."

Can a Cold Plunge Cause Blood Clots?

Cold water can seem like it should thicken the blood, so people concerned about deep vein thrombosis (DVT) often ask about it. A DVT is a blood clot in a deep vein, usually in the leg.

Dr. Laverdiere says he is not aware of hard evidence linking routine cold immersion to either a higher or a lower clot risk. Body temperature can affect clotting at the extremes, he notes, such as in someone who is severely hypothermic. A routine plunge is a different situation.

"There's no robust evidence of routine cold plunges altering your risk of a blood clot," he says.

Why Saunas and Hot Tubs Can Make Swollen Legs Feel Worse

Heat does the opposite of cold. Veins widen as they warm, and in legs with weakened vein valves, that can mean more swelling and heaviness after a session.

Chronic venous insufficiency (CVI) is the condition behind most varicose veins. The one-way valves inside the leg veins stop closing properly, and blood that should travel up toward the heart slips back down and pools. According to Cleveland Clinic, CVI affects about 1 in 20 adults.

Harvard Health Publishing describes the same pattern in warm weather. Heat dilates small veins and lets extra fluid seep into the surrounding tissue, which is why standing in hot weather can leave ankles noticeably swollen.

Saunas are often praised for boosting circulation. For damaged veins, Dr. Laverdiere says, more flow is not automatically better.

"Healthy veins are a one-way road. Unhealthy veins become a two-way road," he says. "If there's more blood flowing through that road, that's more blood that could potentially come back down the veins in the wrong direction."

How much that matters differs from one patient to the next, he adds, and it is hard to predict in advance.

What About Hot Tubs and Vein Health?

Hot tubs work on the same principle, with the legs fully submerged in hot water. According to Harvard Health Publishing, the high temperature in a hot tub or sauna dilates blood vessels and lowers blood pressure, while the pressure of the water increases the heart's workload. The warmth that widens veins in a sauna widens them in a hot tub as well, so legs that swell after a sauna may react the same way to a long soak.

What a Cold Plunge or Sauna Will Not Do

We asked Dr. Laverdiere to finish one sentence: A cold plunge will not...

"A cold plunge will not definitively cure your venous symptoms," he says. "It can help with temporary improvement in symptoms, but ultimately the underlying issue is structural inside the vein, and a cold plunge will not treat that structural damage." – Dr. Laverdiere

His answer for saunas was the same. Both can bring temporary relief. Neither can repair a vein valve that no longer closes.

That structural problem is what vein treatment addresses. At CVR, board-certified vein specialists use duplex ultrasound to map blood flow in the leg veins and pinpoint which valves have failed. Minimally invasive, office-based procedures, such as radiofrequency ablation, laser ablation, and ultrasound-guided foam sclerotherapy, close the damaged vein so blood reroutes through healthy veins nearby.

Saunas and Cold Plunges After Vein Treatment

Patients who build saunas or cold plunges into their routine often ask how long they will need to give them up after a procedure. For Dr. Laverdiere's patients, the answer is one week.

"For my patients who routinely use cold plunges or saunas, I have them wait seven days after the procedure, and then they're allowed to resume their normal activity," he says. "That's purely from an infection risk standpoint, rather than anything about the procedure itself."

Vein procedures enter the skin with a needle or, sometimes, a very small incision, and those entry points need time to close. Cleveland Clinic's sclerotherapy aftercare guidance, for example, advises against hot baths, whirlpools, and saunas for 48 hours after treatment. Timing varies by procedure, so follow the specific instructions your vein physician gives you.

The Question to Ask Before You Step In

Dr. Laverdiere's final piece of advice had little to do with veins. Before stepping through a sauna door or into an ice bath, he says, the most important thing to be certain of is your heart health.

"You would want to use significant caution in someone with heart failure or advanced cardiac disease, where if their heart rate gets up to 150 beats per minute, it could become catastrophic. Like anything in medicine and anything in life, there's a potential for it to be harmful if it's not the right scenario." – Dr. Laverdiere 

Cold brings its own strain. According to Cleveland Clinic, cold plunging can trigger a sudden rise in breathing, heart rate, and blood pressure, which can be dangerous for people with heart conditions, high blood pressure, or stroke risk.

People living with chronic leg swelling or lymphedema should check first, too. Dr. Laverdiere says the decision is individual for these patients, and he wants a patient's primary care physician and full care team in agreement before sauna use begins.

"It is a cardiovascular exercise. It truly is," he says.

Relief That Lasts Longer Than an Afternoon

A sauna or a cold plunge can make your legs feel better for a few hours. If they feel heavy, achy, or swollen again by evening, the cause sits inside the vein, and it responds to treatment.

Center for Vein Restoration is the nation's largest physician-led vein practice, with 130+ locations across 23 states, 100+ board-certified vein doctors, and a 98 percent patient satisfaction rate. Medically necessary vein treatment is covered by most insurance plans, including Medicare and Medicaid.

Cody Laverdiere, DO, is a board-certified emergency medicine physician and vein specialist who brings the diagnostic precision and calm under pressure of emergency care to the minimally invasive treatment of venous disease. His approach centers on educating and empowering patients to make confident, informed decisions about their health. He is the lead physician at Center for Vein Restoration in Bend, Oregon.

Frequently Asked Questions

Q: Is a cold plunge good for varicose veins? 
A: A cold plunge can temporarily shrink veins and ease heaviness and swelling for several hours. It does not repair the damaged valves that cause varicose veins.

Q: Why do my legs swell after a sauna or hot tub? 
A: Heat widens veins, and when vein valves are weak, more blood and fluid collect in the lower legs. Swelling that returns after every session is worth a vein evaluation.

Q: Do cold plunges increase the risk of blood clots? 
A: Dr. Laverdiere is not aware of strong evidence that routine cold plunges raise or lower DVT risk. Clotting can change at extreme body temperatures, such as severe hypothermia.

Q: How long should I wait to use a sauna or cold plunge after vein treatment? 
A: Dr. Laverdiere has his patients wait seven days to lower the risk of infection where the skin was entered. Your vein physician will give you instructions specific to your procedure.

Q: Who should avoid saunas and cold plunges? 
A: People with heart failure, advanced heart disease, high blood pressure, or a higher stroke risk should talk to their doctor first. Anyone with chronic leg swelling should also check with their care team before starting. 

Q: Can saunas or cold plunges replace vein treatment?
A: No. Both offer short-term relief, but only treatment addresses the failed valves behind varicose veins and venous insufficiency.