Written by Joseph Berridge, Founder of Joga Yoga

Updated September 2026

We run heated classes daily in Canggu, where the humidity is already high before anyone turns a heater on. So we see the whole range of this, most often in trainees who’ve arrived from a dry climate and assumed their usual practice would translate.

Below is each symptom, what causes it, and the line between “this is the heat doing its job” and “get out of the room.”

Which One Are You Dealing With?

Why You Feel Wiped Out

Your body did two jobs at once. It moved through the poses, and it tried to cool itself in a room that won’t let it.

Normally you sweat, air moves across your skin, and the evaporation cools you. In a heated room that mechanism stalls. The air is already hot and often already humid, so the sweat keeps coming without doing much cooling. Your heart rate stays elevated for the duration, and a systematic review of 43 hot yoga studies confirmed that both core temperature and heart rate rise more than in an unheated class.

Here’s the part that surprises people. That same review found the energetic demand was not higher than non-heated yoga. So the exhaustion isn’t because you worked harder. It’s thermal load plus fluid loss, and those feel identical to having trained hard.

Source: Systematic review of 43 hot yoga studies, 942 participants.

Flat for a few hours is normal, particularly in your first few weeks. Wiped out for two days usually means you arrived underhydrated. One researcher at Columbia has put the proportion of hot yoga participants found to be dehydrated at around half, which matches what we see in a class of twenty.

What actually helps

• Drink through the whole day before class, not a litre in the car park
• Eat something within an hour afterwards. Skipping the meal is what turns tiredness into next-day fog.
• Replace sodium, not just water. Coconut water, an electrolyte tab, or salt on your food.
• Give it four to six weeks. Heat adaptation is real, and the fatigue drops off noticeably.

Headaches

Fluid and electrolyte loss, nearly every time. Sodium leaves in sweat alongside water, and if you replace only the water you can end the class with the balance further off than when you started.

Practical fix: hydrate across the day beforehand, and put something with salt in it into your post-class drink. Drinking a litre of plain water immediately afterwards can actually make a sodium-driven headache slightly worse.

A headache arriving with confusion, vomiting or a very high temperature is a different thing entirely. That’s not a rehydration problem, and it needs medical attention rather than rest.

Dizziness and Lightheadedness

This is the symptom on the page that matters most, so it gets the plainest language.

Mild lightheadedness when you stand up quickly from a forward fold is common and passes in seconds. Genuine dizziness is a stop signal. Cleveland Clinic lists dizziness, lightheadedness and being unable to take a full breath as the things to watch for in a heated class, and their advice is to return to a stable position or leave the studio until you feel better.

Nausea

Three usual causes, in order of how often we see them.

What you ate, and when. A full meal within about two hours of a heated class is the most common culprit. Digestion competes with everything else your body is trying to do in the heat.

Inversions plus heat. Going upside down when you’re already overheated is a reliable way to feel sick. Skip the inversions on days you’re struggling with the room.

Overheating itself. If nausea comes with dizziness or a headache, treat it as the heat rather than your stomach, and use the list above.

Soreness That Lasts Days

This one has a specific cause worth understanding, because it’s the main injury risk in heated practice.

Heat makes you feel more flexible than you are. Tissue is warmer and more compliant, the usual end-of-range sensation arrives later, and you go further into a pose than your body is actually prepared for. You don’t notice at the time. You notice two days later.

The room hides effort as well as range. Because you’re already hot and dripping, the normal cues that tell you you’re working hard get drowned out.

So: go to about 80% of your available range in a heated class, not 100%. Judge your depth by what you can do in an unheated class, not by what the room lets you reach.

The Hot Yoga Hangover

The informal name for waking up the day after a class feeling headachy, foggy and drained. There’s nothing mysterious in it. It’s dehydration, sodium loss and often a skipped meal.

Prevention is dull and effective: hydrate the day before, replace salt afterwards, eat a real meal within the hour, and don’t schedule your first heated class for the morning after a late night. Alcohol and heated yoga are a genuinely poor combination.

Skin Breakouts

Heavy sweat sitting on skin, in tight clothing, in a warm room. Shower and change promptly rather than driving home in your kit, and gently, since scrubbing an irritated face makes it worse. If you have eczema, the heat and sweat can trigger a flare.

And to clear up something repeated constantly in this category: sweating does not remove toxins. Sweat is mostly water and electrolytes. Detoxification is what your liver and kidneys do. Heavy sweating tells you the room is hot and nothing else, which is also why it doesn’t mean you burned more calories.

What the Research Actually Found

The largest review to date pooled 43 studies covering 942 participants, three quarters of them women, across rooms from 30 to 52°C. Its conclusions are more balanced than either side of the usual argument.

Read together: the safety profile is broadly reassuring for healthy people, the benefits are real but not exclusive to heat, and the marketing claim that heated yoga beats everything else doesn’t hold up.

Who Should Skip Heated Classes

Hot yoga generally isn’t advised during pregnancy or for people with a heart condition, and the heat can aggravate asthma.

Beyond that, talk to your doctor first if you have cardiovascular or respiratory problems, take medication affecting how you handle heat or fluid balance, or have a history of heat illness. Perimenopausal and menopausal hot flushes can make a heated room considerably less comfortable, though there’s no reason to think it’s unsafe.

Stimulants raise your risk of heat-related side effects in this environment. That includes a heavy pre-workout or several coffees, not just the obvious things.

If you’re new to yoga entirely, take a few unheated beginner classes first. You’ll learn where your range actually is, which is exactly the information the heated room takes away from you.

Frequently Asked Questions