- Cold plunging, or cold water immersion (CWI), is a wellness trend involving submersion in water between 50°F and 68°F. It’s linked to benefits like reduced stress, mood improvement, and immune support.
- 2025 research shows regular cold plunging may reduce sickness absences by 29% and improve cellular resilience through mechanisms like autophagy (cellular repair).
- Short-term effects include increased inflammation and stress hormones, while long-term practice boosts immune function and stress adaptation.
- Risks include cold shock, hypothermia, and heart strain, especially for people with preexisting health conditions. Safety guidelines recommend starting slow and keeping sessions brief (2–10 minutes at 50°F–60°F).
- Key tip: Even 11 minutes per week, spread across multiple sessions, can offer benefits.
Cold plunging offers potential immune benefits, but safety and consistency are crucial. Continue reading for detailed findings, risks, and safe practice guidelines.
2025 Scientific Evidence on Cold Plunging and Immunity
2025 Research Studies Overview
In 2025, a systematic review and meta-analysis examined 11 studies involving 3,177 participants, exploring cold exposure methods like baths and showers at temperatures ranging from 45°F to 59°F (7°C to 15°C). The exposure durations varied from 30 seconds to 2 hours, giving researchers a chance to compare different protocols and their effectiveness [5].
A noteworthy randomized trial involving 3,018 participants found that daily cold water immersion (lasting 30–90 seconds) reduced sickness-related absences by 29% compared to the control group (incident rate ratio: 0.71, P = 0.003) [5].
At the University of Ottawa, a focused study was conducted with ten healthy young men. They underwent cold water immersion at 57°F (14°C) for one hour over seven consecutive days. Blood samples collected before and after the protocol revealed key cellular responses [6].
"Repeated cold exposure improves autophagic function, a critical cellular protective mechanism. This enhancement allows cells to better manage stress and could have important implications for health and longevity."
- Professor Kenny, Full Professor at uOttawa's School of Human Kinetics and Director of HEPRU [6]
These findings highlight how short-term and long-term cold exposure can differently influence immune function.
Short-Term vs. Long-Term Effects
The 2025 studies uncovered notable differences between the immediate and sustained effects of cold plunging on the immune system. The meta-analysis found no measurable changes in immune markers immediately after, or even one hour post-immersion [5].
However, longer-term exposure showed promising results. For example, regular cold water immersion was linked to a 29% reduction in workplace sickness absences [5].
The University of Ottawa study also shed light on how the body adapts over time. Postdoctoral fellow Kelli King noted significant improvements in cellular resilience after the seven-day protocol:
"By the end of the acclimation, we noted an improvement in the participants' cellular cold tolerance. This suggests that cold acclimation may help the body effectively cope with extreme environmental conditions." [6]
These findings suggest that repeated exposure enhances cellular resilience and autophagic function, but these benefits require consistent practice over days or weeks. For instance, one study found that a short cold water immersion (12 minutes at 50°F/10°C) following endurance exercise temporarily increased neutrophil counts but had no effect on lymphocytes, monocytes, or systemic inflammatory markers 24 to 48 hours afterward [5].
Research Strengths and Limitations
The 2025 research offers valuable insights, supported by several strengths. Many studies used rigorous randomized controlled designs, which reduce the risk of confounding variables [5]. The University of Ottawa study, with its precise temperature control and standardized blood sampling, adds further credibility. Additionally, the large sample size in the pragmatic trial bolsters the statistical reliability of its findings. While immediate immune effects appear limited, the evidence strongly supports the long-term benefits of regular cold exposure.
That said, there are limitations to consider. Many studies had small sample sizes and lacked diversity in participant demographics, which makes it harder to apply the findings broadly [5]. The inability to blind participants in cold exposure studies introduces potential bias, as participants are aware of whether they are exposed to cold or warm water. Moreover, the wide variation in protocols - ranging from temperatures of 45°F to 59°F and durations between 30 seconds and 2 hours - complicates comparisons across studies. Self-reported outcomes, such as illness symptoms and sick days, also add a layer of subjectivity. Lastly, individual responses to cold exposure can differ significantly based on factors like age, fitness level, and prior experience with cold immersion.
Despite these challenges, the collective findings suggest that regular cold exposure holds promise for improving immune function over time.
Does Cold-Water Immersion Boost Your Immune System?
How Cold Plunging Affects Immune Function
The science behind cold plunging reveals how it can play a role in strengthening the immune system. When you immerse yourself in cold water, your body initiates a series of responses that, over time, can lead to enhanced immune function. These responses include immediate reactions and longer-term adaptations, which work together to improve overall health. Let’s explore how these processes unfold.
Acute Inflammation Response
Cold water immersion sparks an inflammatory response as your body adjusts to the sudden drop in temperature. While inflammation is often seen as something to avoid, in this case, it’s a vital part of the body’s adaptation process. A 2025 meta-analysis highlighted that inflammation levels significantly increased immediately after cold plunging (SMD: 1.03, 95% CI: 0.37, 1.68, p < 0.01) and remained elevated an hour later (SMD: 1.26, 95% CI: 0.59, 1.94, p < 0.01) [7]. This reaction is driven by the sympathetic nervous system, which kicks into high gear during cold exposure [9].
"The immediate spike in inflammation is the body's reaction to the cold as a stressor. It helps the body adapt and recover and is similar to how exercise causes muscle damage before making muscles stronger, which is why athletes use it despite the short-term increase." - Ben Singh, Study Coauthor [8]
This process mirrors how exercise temporarily stresses the body to ultimately make it stronger. Beyond inflammation, cold plunging triggers cellular activities that further support immune resilience.
Cellular Repair and Autophagy
One of the more fascinating benefits of cold plunging is its ability to stimulate cellular repair mechanisms. A key process here is autophagy, the body’s way of cleaning out damaged cellular components and recycling them. A study from the University of Ottawa found that just seven days of cold water immersion at 57°F (14°C) significantly boosted autophagic activity and cellular resilience [6]. This process helps clear out toxic protein build-ups and damaged organelles that could otherwise disrupt immune function [10].
"Our findings indicate that repeated cold exposure significantly improves autophagic function, a critical cellular protective mechanism. This enhancement allows cells to better manage stress and could have important implications for health and longevity." - Professor Kenny [6]
Cold exposure also activates proteins that influence gene expression and improve lymphatic function [4][11]. Additionally, spending one hour in 57°F (14°C) water can increase metabolic rate by 350%, providing the energy needed for cellular repair and immune support [11].
Stress Hormone Regulation
Cold plunging also helps regulate stress hormones, which are closely tied to immune health. When you enter cold water, your body releases a mix of hormones and neurotransmitters like cortisol, norepinephrine, dopamine, serotonin, and β-endorphins [2].
Professor Mike Tipton from the University of Portsmouth describes this reaction:
"When you immerse yourself in cold water, your body undergoes the cold shock response. You get rapid breathing, a spike in heart rate and a surge of stress hormones such as adrenaline and cortisol." - Mike Tipton [3]
While this initial surge might sound alarming, regular cold exposure helps your body adapt and manage cortisol levels more effectively over time [12]. Studies show that stress levels significantly drop 12 hours after cold plunging [5]. Furthermore, cold exposure can increase norepinephrine levels by 530% and dopamine by 250%, which not only boosts immune cell activity but also enhances focus and mood [11].
To get the most out of cold plunging without overloading your system, experts suggest keeping sessions brief - around 90 seconds [3]. Consistent, controlled exposure trains your body to handle stress better, reducing the impact of chronic stress, which is a known factor in weakening immune defenses.
Benefits and Limitations for Immune Health
Research from 2025 highlights both the potential immune-boosting effects and the risks of cold plunging.
Health Benefits
Recent studies have built on earlier findings, showing that cold plunging may help reduce illness-related absences. A 2025 meta-analysis of 11 studies involving 3,177 participants found a 29% reduction in sickness-related absences among those who practiced cold plunging regularly [21].
Cold exposure appears to enhance immune function by increasing the production of white blood cells, which play a vital role in fighting infections [2][15]. It also triggers a controlled stress response, which helps the body adapt to stress more effectively. In fact, research shows that stress levels can decrease for up to 12 hours after cold exposure [21].
Tara Cain, a researcher at the University of South Australia, emphasizes that cold water exposure doesn’t have to involve full immersion:
"Benefits may be gained from cold showers as well... with one study reporting that participants who took regular cold showers experiencing a 29% reduction in sickness absence." - Tara Cain [21]
Cold plunging also activates cellular repair processes like autophagy, which may help protect against disease and slow down cellular aging [6].
While these findings are promising, it’s important to consider the risks that come with cold plunging.
Limitations and Risks
Despite its potential benefits, cold plunging isn’t without dangers. One of the primary concerns is the cold shock response, which can cause a sudden spike in heart rate, blood pressure, and breathing rate [19]. Additionally, water conducts heat away from the body up to 25 times faster than air, significantly increasing the risk of hypothermia - even in moderately cold water [20].
François Haman, a biologist at the University of Ottawa, warns about the underestimated risks:
"What people don't realize is the health benefits are maybe not what they think they are, and they always forget about the risks... Ice water can actually bring tremendous risks." - François Haman [18]
Improper cold plunging can lead to conditions like hypothermia or frostbite. Water temperatures below 60°F can be life-threatening within minutes, and typical cold plunging temperatures (55°F–69°F) still carry risks [17].
Certain groups face higher risks, including individuals with heart conditions, high blood pressure, diabetes, or poor circulation. People taking medications that affect heart rate or blood pressure should also exercise caution [16]. Additionally, the risk of drowning increases due to cold shock and disorientation, especially in open water [16].
Another limitation is the lack of long-term data on the sustained immune benefits of cold plunging. Individual responses vary depending on factors like stress levels, hydration, and overall health. Some benefits, such as improved well-being from cold showers, may fade within three months of stopping the practice [21]. For athletes, cold water immersion can interfere with strength training adaptations, potentially limiting long-term muscle growth and performance, although it does not seem to impact endurance training in the same way [14].
Benefits vs. Risks Comparison
Here’s a side-by-side look at the main benefits and risks of cold plunging:
| Potential Benefits | Potential Risks |
|---|---|
| Reduced sickness absence [21] | Cold shock response [19] |
| Increased white blood cell production [15] | Hypothermia and frostbite [19] |
| Enhanced stress adaptation [15] | Heart strain [18] |
| Improved cellular repair mechanisms [6] | Drowning risk due to cold shock [16] |
| Reduced inflammation [14] | Interference with strength training adaptations [14] |
| Better mental well-being [14] | Medication interactions [16] |
While cold plunging offers immune and stress-related benefits, the risks - especially for those with preexisting health conditions - cannot be ignored. As François Haman points out, cold water immersion should be approached as a method for stress management rather than a universal solution [18]. Proper techniques, gradual adaptation, and a thorough evaluation of personal health are essential for safe and effective practice.
Safe Cold Plunging Recommendations
Incorporating cold plunging into your routine can be a great way to boost your immune system and overall wellness. However, following the right guidelines is key to doing it safely and effectively.
Temperature, Duration, and Frequency Guidelines
Research suggests that keeping water temperatures between 50°F and 60°F (10°C to 15°C) strikes the perfect balance between triggering beneficial physiological responses and minimizing risks for healthy adults [23][24]. This range is manageable for most people and provides the desired effects without pushing the body too far.
"The general science-backed guideline is: Time: 2–10 minutes, Temperature: 10°C to 15°C (50°F to 59°F). Avoid staying in longer than 15 minutes unless you're highly adapted, and never go below 5°C (41°F) without professional supervision. Always monitor your body for signs of hypothermia or discomfort." [22]
If you're new to cold plunging, start slow. Begin with sessions lasting 30 seconds to 1 minute, and gradually work up to the recommended 2–10 minutes. Never extend beyond 15 minutes unless you're highly accustomed to the practice [22][23][24].
For immune support and general wellness, aim for 3–4 sessions per week. Interestingly, as little as 11 minutes per week, spread across multiple sessions, can yield noticeable benefits [22][23][24]. Timing matters, too. Early morning plunges can increase dopamine levels by up to 250%, promoting alertness and focus. If you’re using cold plunging for workout recovery, the sweet spot is within 2–4 hours after intense exercise [22].
"Remember, even a two-minute plunge at the right temperature can spike your dopamine by 250%. That's not hype - that's your neurochemistry working for you." [22]
By following these guidelines, you can safely explore cold plunging and decide if it aligns with your health goals.
Who Should and Shouldn't Cold Plunge
Not everyone is suited for cold plunging, and understanding your personal health needs is just as important as following the proper protocols. Certain medical conditions make cold plunging unsafe. People with heart conditions, high blood pressure, diabetes, peripheral neuropathy, poor circulation, venous stasis, or cold agglutinin disease should avoid it altogether [26]. Pregnant women should also steer clear, as it may pose risks to both mother and baby [28]. Older adults should approach cold plunging cautiously due to slower recovery from cold shock and a higher risk of complications [29].
Dr. Van Dien emphasizes the importance of consulting a healthcare provider before starting:
"Understanding your medical comorbidities and what risk they pose is extremely important before cold plunging." [29]
Beginners should take extra precautions. Ease into the practice by starting with cold showers to let your body adjust before attempting full-body immersion [30]. Always have someone nearby during your first sessions [25][27], and avoid alcohol or heavy meals beforehand, as these can impair your body’s ability to regulate temperature [27].
Dominic King, DO, offers this advice for beginners:
"Start low and go slow. Don't go too cold and don't go for more than five minutes, just to make sure you can tolerate it." [26]
At-Home Cold Plunge Equipment Resources
Once you’re familiar with the safety guidelines, selecting the right equipment becomes a crucial step. The effectiveness and safety of your cold plunging practice largely depend on the quality of your setup, including temperature control, water cleanliness, and safety features.
Professional-grade cold plunge tubs are ideal because they provide precise temperature control, efficient cooling, and built-in safety mechanisms. These features help maintain the recommended 50°F to 60°F range, ensuring both safety and the desired immune system benefits.
For those navigating the equipment landscape, ColdPlungeTubs.com is a helpful resource. The site offers expert reviews, detailed comparisons of cold plunge tubs, and practical guides covering everything from installation to maintenance. This ensures you can create a setup that aligns with recognized safety standards.
When choosing equipment, focus on units with digital temperature displays, automatic shut-offs, and filtration systems to maintain water quality. Consulting with experts through ColdPlungeTubs.com can provide additional guidance to ensure your setup is safe and effective for regular use.
Conclusion: 2025 Evidence Summary
The 2025 research highlights that cold plunging doesn't cause immediate changes in immune function but may lead to a 29% reduction in sickness absences when practiced consistently. A systematic review and meta-analysis found no significant immediate or short-term effects on immune function from cold-water immersion. However, a narrative analysis pointed to longer-term benefits, particularly for those who made cold showers a regular habit[1].
Repeated exposure to cold water works as a non-infectious stressor, stimulating the immune system. One study revealed that seven consecutive days of cold-water immersion enhanced cellular resilience and autophagic function, aiding cells in managing stress more effectively[6][13]. These findings suggest that regularity and gradual adaptation are essential to achieving any potential immune-related benefits. A cautious, long-term approach appears to be the most effective way to maximize the advantages of cold plunging.
That said, safety concerns cannot be overlooked. Experts caution against improper use, especially for individuals with preexisting health conditions, as the risks can be considerable.
For those interested in trying cold plunging, the evidence points to a balanced approach. Spending just 11 minutes per week in cold water, spread across several sessions, may offer immune benefits while keeping risks low[28]. Starting with cold showers and gradually moving to full immersion is recommended. Using professional-grade equipment with precise temperature controls can further ensure safety.
The 2025 findings suggest that cold plunging, when done thoughtfully and safely, can be a helpful tool for supporting immune health. However, it’s crucial to have realistic expectations and take proper precautions to avoid potential risks.
FAQs
What are the long-term immune benefits of regular cold plunging compared to its short-term effects?
Cold plunging, when practiced regularly, has been linked to strengthening the immune system by stimulating white blood cell production and enhancing the activity of immune cells. Over time, this can help the body fend off infections more efficiently while also supporting cellular health and potentially contributing to a longer, healthier life.
In the short term, the benefits of cold plunging are centered around stress relief, improved sleep quality, and reduced inflammation. These immediate effects can aid recovery and boost mental clarity. Meanwhile, its long-term advantages focus on fortifying the immune system and promoting overall wellness. Adding cold plunging to your routine can serve as a powerful practice for both short-term recovery and long-term health.
What’s the safest way to start cold plunging, especially for someone with existing health conditions?
If you have any existing health conditions, checking in with your doctor before trying cold plunging is a must. Immersing yourself in cold water can impact your cardiovascular system, potentially raising blood pressure or placing extra strain on your heart.
To ease into it safely, start with brief sessions - just 1 to 2 minutes - in water temperatures ranging from 50–60°F. This gradual approach gives your body time to adjust. Pay close attention to how you feel, and skip cold plunging if you're unwell or showing signs of illness, as it could worsen certain issues. Above all, prioritize your safety and listen to what your body is telling you.
How can I safely reap the immune-boosting benefits of cold plunging?
To safely enjoy the immune-supporting benefits of cold plunging, it's important to ease into the practice gradually. Start with short sessions, lasting about 1 to 3 minutes, and slowly extend the duration as your body gets used to the experience. Keep the water temperature above 50°F to reduce the risk of hypothermia, and avoid sudden immersion in water colder than 60°F, as this can be dangerous.
Listen to your body throughout the process. If you feel any discomfort or notice anything unusual, stop immediately. It's also wise to consult a healthcare professional before beginning cold water therapy, especially if you have any existing medical conditions. Taking these precautions can help you enjoy the benefits while staying safe.