We humans love suffering. We convince ourselves that sweating profusely in hot yoga or dunking into an ice bath is somehow ‘good’ for us. And maybe… it is?

I’ve run a few “hot yoga, cold plunge” workshops, and while everyone is different, their reactions are almost identical. We crank up the heat—both in the room and in the practice—until the idea of a freezing plunge starts to sound... weirdly appealing.

Then comes the moment of truth—people step into the cold water. A sharp breath (or 100). The first 30 seconds? Pure resistance. But then, a shift happens. Acceptance. I wouldn’t call it comfort, but something clicks. And when they step out? Euphoric.

You might already know that hot yoga makes you feel like a glorious, sweaty puddle of achievement (if not, check out my blog on Sweating Buckets: A Guide to Hot Yoga & Its Many Forms for all the details). And an ice bath (or cold plunge) will make you question your sanity. But the extra magic happens when you combine the two. In fact in Finland, it's common to go from a 200°F sauna straight into an ice-cold lake. Because why ease into suffering?

Ice Bath vs. Cold Plunge: What's the Difference?

People often use ice bath and cold plunge interchangeably, but there’s a subtle difference. Knowing the difference can help you pick the right one—whether you want benefits without the extreme suffering, or you just enjoy making life harder for yourself.

• Cold Plunge – Any immersion in cold water, typically between 10°C - 15°C (50°F–59°F), whether it's a natural body of water or a controlled setting.

• Ice Bath – A more extreme version of a cold plunge, usually below 10°C (50°F) and containing actual ice to keep temperatures near freezing.

Which one is better? It depends on your goal. A cold plunge is more accessible and still delivers benefits, while an ice bath amplifies the intensity—great for deeper recovery, but also significantly harder to endure.

Heat vs. Cold: What Happens in the Body?

Before diving into why combining heat and cold is so powerful, let’s break them down separately.

What happens in Heat Exposure (Sauna, Hot Yoga, Infrared Heat)

Vasodilation: Blood vessels widen, increasing circulation and delivering nutrients to muscles.
Cardiovascular Boost: Heart rate increases, mimicking moderate exercise.
Heat Shock Proteins: These little stress-fighters help cells repair themselves. Think of them as your body's built-in recovery crew.
Endorphin Release: Heat exposure increases the release of feel-good neurotransmitters, contributing to a sense of well-being.

What happens in Cold Exposure (Ice Baths, Cold Showers, Winter Swimming)

Vasoconstriction: Blood vessels constrict to preserve core temperature, which can improve circulation over time.
Metabolic Boost: Cold exposure activates brown fat (more on this later), which burns calories to generate heat.
Dopamine Spike: A cold plunge can boost dopamine levels by 250%—about the same increase as taking a hit of nicotine. (But healthier!) and it remains elevated for hours after exposure
Anti-Inflammatory Response: Cold reduces swelling, speeds up recovery, and lowers overall inflammation.

Why Pair Hot & Cold? The Science-Backed Benefits

Alternating between heat and cold exposure can amplify health benefits:

Cardiovascular Flexibility: Switching between vasodilation (heat) and vasoconstriction (cold) exercises blood vessels, enhancing their elasticity and improving circulation.
Enhanced Recovery & Reduced Inflammation: Cold therapy reduces muscle soreness and swelling, while heat promotes blood flow and oxygen delivery to tissues.
Improved Stress Response: Both heat and cold activate the sympathetic nervous system, training the body to handle stress more effectively.
Increased Metabolism: Cold exposure stimulates brown fat activity, boosting calorie burning. Ending on cold can prolong this effect.
Mental Resilience: Enduring temperature extremes can build mental toughness and resilience.

The Science of Brown Fat: Why It's the 'Good' Fat

Not all fat is created equal. Brown fat is considered the "good" fat because it burns calories to generate heat, whereas white fat is the "storage" fat that accumulates when we consume more energy than we use.

• Brown fat is metabolically active, meaning it helps regulate body temperature and burns energy rather than storing it.

• White fat stores excess energy, and an excessive amount is linked to obesity and metabolic issues.

• Cold exposure activates brown fat, making your body more efficient at burning calories and maintaining warmth.

• Brown fat declines with age, but staying physically active and incorporating deliberate cold exposure can help retain or even increase it.

• Heat also plays a role—interestingly, warm skin can stimulate brown fat activity, though not as effectively as cold.

If full-body immersion feels unbearable, keeping your hands and feet out of the water at first can help you tolerate the cold while still activating brown fat.

How to Do Hot & Cold Therapy (Without Crying)

If you’re sold on the idea but don’t want to throw yourself into a freezing lake just yet, here’s how to get started:

Hot First, Then Cold – Heat opens up blood vessels; cold closes them. Ending on cold gives you longer-lasting benefits.
How Long? – Studies suggest 11 minutes of cold exposure per week (spread across 2-3 sessions) and 10-15 minutes of heat per session for optimal effects.
What Counts as Cold? – Anything that makes you think, “This is cold, and I want to get out, but I can safely stay in.”
Ease In – Try finishing your shower with 30 seconds of cold before upgrading to ice baths.
Move in the Cold – Staying still creates an insulating thermal layer around you; moving breaks it and makes the cold more effective.

For full disclosure, when I first tested out the cold plunge —I filmed myself, thinking I’d create a promo video. For the whole four minutes (fine, two minutes), I swore profusely. There was no serene, enlightened moment—just me cursing at the water. So whilst I write about the benefits of this practice, I am still too chicken to fully take the plunge!

Random Facts

The highest officially recorded air temperature on Earth is 56.7°C (134.1°F), measured on July 10, 1913, at Furnace Creek Ranch in Death Valley, USA. (rather aptly named)
The lowest recorded temperature is -89.2°C (-128.6°F), observed at the Soviet Union's Vostok Station in Antarctica on July 21, 1983.
The Sahara silver ant can withstand some of the highest temperatures of any terrestrial animal, up to 50°C (122°F). (but only for 10 minutes. Any longer and they literally cook.)
Longest ice bath: Josef Köberl stayed in ice for 3 hours, 1 minute in 2021.
Longest sauna sit: A Finnish competition reached 110°C (230°F) for over 16 minutes before being banned.
Siberian salamanders can survive frozen for YEARS and thaw out unharmed.
David Blaine once spent 63 hours encased in ice. (Because of course he did.)

Are You Brave/Bonkers Enough to Try This?

Not everyone feels the need to marinate in their own sweat before willingly submerging themselves in something that feels like liquid death. And that’s fair. But if you’re looking for better recovery, improved stress resilience, and a metabolism boost, this hot and cold combo might just be your new best friend.

I sometimes run workshops that combine heat and cold therapy so keep an eye on the workshops page, they’re definitely worth trying if you get the chance. At the very least, you’ll walk away with a heroic story and possibly a newfound respect for your ability to endure ridiculous things.

That’s it—hot, cold, and everything in between. Now, are you brave enough to try it … or stay cozied up with your central heating?