The Science Behind Hot & Cold Therapy: Why Saunas and Ice Baths Work
More Than Just a Trend
You’ve probably seen it all over Instagram—people plunging into icy water before jumping into a steaming sauna. What might look like just another wellness craze is actually backed by decades of research. Known as contrast therapy or hot and cold immersion, this practice has been used by athletes, monks, and even ancient cultures to restore balance in the body and mind.
The Hot & Cold
At WellNest in London Bridge, hot & cold therapy is at the heart of our spa experience. Whether you’re here to recover after training, boost your energy, or simply de-stress, the science behind alternating heat and cold explains why it works so powerfully.
How Hot & Cold Therapy Works
Step 1: The Heat (Sauna)
Increases blood flow: Sauna heat causes your blood vessels to dilate (vasodilation), improving circulation.
Flushes toxins: Sweating removes impurities while stimulating your lymphatic system.
Releases endorphins: The warmth relaxes your nervous system, lowering cortisol (the stress hormone).
Step 2: The Cold (Ice Bath)
Constriction and recovery: Cold immersion narrows your blood vessels (vasoconstriction), reducing inflammation.
Boosts metabolism: Cold triggers brown fat activation, helping burn calories and regulate body temperature.
Mental resilience: The shock of cold teaches your body to adapt, improving focus and discipline.
Step 3: The Contrast Effect
When you move between hot and cold, you’re essentially training your vascular system like a muscle. The pumping action of dilation and constriction creates a natural “internal workout” for your body, flushing out waste and accelerating recovery.
Proven Benefits of Hot & Cold Therapy
Faster Muscle Recovery
Athletes from Premier League footballers to Olympic swimmers swear by it. Research shows alternating heat and cold reduces delayed onset muscle soreness (DOMS).Stronger Immune System
Cold plunges stimulate white blood cell production, while saunas help boost overall immune response. Together, they create a powerful natural defence.Reduced Stress & Anxiety
The combination of endorphins, dopamine, and improved circulation helps combat anxiety and mental fatigue. Many members at WellNest say they leave feeling “lighter and calmer.”Better Sleep Quality
Evening sauna sessions lower cortisol and promote melatonin production. Cold immersion afterwards helps regulate body temperature, preparing your body for deep rest.Increased Energy & Focus
The cold triggers norepinephrine, a neurotransmitter that boosts alertness. That’s why so many London professionals use morning plunges as a “natural coffee.”
Ancient Wisdom Meets Modern Science
Contrast therapy isn’t new. The Finnish sauna tradition, Japanese onsen baths, and Roman thermal spas all included hot & cold rituals. What’s new is the science: modern studies confirm what ancient cultures already knew—this ritual heals and strengthens both body and mind.
What to Expect at WellNest
At WellNest, we’ve designed our spa to make hot & cold therapy accessible, safe, and transformative:
Guided sessions with our wellness team for beginners
Self-guided rituals for those who prefer their own flow
Different saunas and ice baths at varying temperatures to suit your level
Relaxation areas where you can pause, breathe, and reconnect
Whether it’s your first plunge or your hundredth, the experience is tailored to your pace.
Tips for First-Timers
Start slow: Begin with 1–2 minutes in the ice bath after the sauna.
Breathe deeply: Controlled breathing calms the shock response.
Alternate 3–4 times: For best results, cycle between hot and cold multiple times.
Stay hydrated: Drink water before and after your session.
Is It Safe for Everyone?
While contrast therapy has broad benefits, people with cardiovascular conditions, pregnancy, or certain medical issues should consult a doctor first. At WellNest, our team is trained to guide you safely through the experience.
Why London Loves Hot & Cold Therapy
In a city that never stops, Londoners are embracing hot & cold rituals as the ultimate reset. It’s efficient, energising, and deeply restorative—perfect for busy professionals, athletes, and anyone craving balance.
Ready to Try It?
If you’re curious to experience the power of contrast therapy, come and join us at WellNest London Bridge.
✨ Book your first spa session here
With regular practice, you’ll discover why this ancient ritual is becoming London’s newest wellness essential.
