Who should not do contrast therapy?
Quick answer
Contrast therapy is contraindicated for people with uncontrolled cardiovascular disease, severe hypertension, Raynaud's disease, open wounds or active skin infections, and those who are pregnant. The rapid blood pressure swings and cardiovascular stress from alternating extreme temperatures pose particular risk for people with compromised heart or vascular function. Anyone with a chronic condition should consult a physician before starting.
Cardiovascular conditions and contrast therapy
The most important contraindications for contrast therapy involve cardiovascular health. The transition from sauna heat to cold water creates rapid and significant blood pressure changes — peripheral blood vessels that were fully dilated in the sauna constrict sharply in the cold, causing blood pressure to spike, while heart rate surges from the cold shock response. For people with uncontrolled or severe hypertension, this pressure spike can reach dangerous levels. Those with a history of myocardial infarction (heart attack), unstable angina, cardiac arrhythmia, or congestive heart failure face elevated risk from the cardiovascular stress of contrast therapy. People with severe or symptomatic aortic stenosis, in which the aortic valve is narrowed and the heart cannot easily adjust to sudden changes in vascular resistance, are particularly vulnerable. Anyone with an active cardiac diagnosis should receive explicit cardiology clearance before starting.
Pregnancy and temperature extremes
Pregnancy is a contraindication for both the extreme heat component and the cold immersion component of contrast therapy. Elevated core body temperature during pregnancy — particularly in the first trimester — has been associated with increased risk of neural tube defects and other developmental concerns. Traditional sauna use at Finnish temperatures of 160–185°F (71–85°C) is generally advised against during pregnancy for this reason. Cold water immersion triggers a significant autonomic stress response including blood pressure spikes and catecholamine release that could theoretically affect placental perfusion and fetal well-being, though research specifically on cold plunge safety in pregnancy is limited. Most obstetric guidelines recommend avoiding both hot tub use and extreme cold immersion during pregnancy. Pregnant individuals should follow their obstetric provider's specific guidance.
Raynaud's disease and cold exposure
Raynaud's disease is a condition in which cold temperatures or emotional stress trigger vasospasm in the extremities — typically the fingers and toes — causing them to turn white, then blue, then red as blood flow shuts down and then returns. Cold water immersion in someone with Raynaud's disease can precipitate a severe and painful vasospastic attack, potentially affecting circulation to extremities in ways that go beyond discomfort to cause tissue damage in severe cases. Even in individuals with mild Raynaud's disease who have tolerated cold exposure in other contexts, the rapid and complete immersion of a cold plunge creates a more intense and uniform cold stimulus than most other cold exposures, increasing the risk of triggering a significant episode. People with Raynaud's should discuss cold exposure with a rheumatologist before attempting cold plunge or contrast therapy.
Skin conditions and open wounds
Open wounds, active skin infections, eczema flares, psoriasis flares, and post-surgical incisions are contraindications for water immersion of any kind, including cold plunge. Immersion in shared water — even in filtered and sanitized studio cold plunge tubs — carries infection risk for compromised skin barriers. Heat from the sauna can exacerbate inflammatory skin conditions during active flares, as elevated skin temperature increases inflammatory mediator activity. People with well-controlled chronic skin conditions such as psoriasis or eczema who are not in a flare period may be able to use contrast therapy but should consult a dermatologist about their specific situation. Fungal infections, particularly athlete's foot, are also relevant: the warm, moist environment of a sauna or pool area can promote fungal growth, and using appropriate footwear in studio environments reduces transmission risk.
Medications that increase risk during contrast therapy
Several classes of medications affect the safety profile of contrast therapy. Diuretics increase fluid and electrolyte loss during sauna sweating, amplifying the dehydration risk. Beta-blockers and certain other antihypertensive medications impair the heart's ability to compensate for the cardiovascular demands of extreme temperature transitions, potentially causing unsafe blood pressure drops or blunted heart rate responses. Vasodilators — medications that dilate blood vessels — can exaggerate the blood pressure drop that occurs in the sauna and immediately after exiting. Central nervous system depressants including sedatives, certain antidepressants, and opioids may impair heat perception and reduce the ability to recognize warning signs. Alcohol, while not a medication, significantly increases contrast therapy risk by impairing judgment, reducing heat perception, and amplifying both the vasodilatory effects of heat and the blood pressure swings of cold immersion. Anyone on prescription medications should review their specific drugs with their prescribing physician before starting contrast therapy.