Hot Yoga: Safety, Hydration and What to Expect in Class

Short answer: hot yoga is yoga practiced in a heated room, usually for an hour or more. In lab testing, a 90-minute Bikram class counted as light-to-moderate exercise, not the 1,000-calorie workout some studios claimed (Pate and Buono). The heat adds real risks of overheating and dehydration, so go in prepared, start with a gentler class, and leave the room if you feel unwell. As of November 2026, that is the balanced view.

Check with a clinician first. Ask your doctor before trying hot yoga if you are pregnant, have heart or blood pressure problems, diabetes, a history of heat illness, or take medication that affects hydration or heart rate. The NHS notes that people with long-term conditions such as diabetes or heart problems are at higher risk of heat exhaustion (NHS). Pregnant women should avoid hot yoga (ACOG).

This guide is general education and not medical advice.

What is hot yoga?

Hot yoga is an umbrella term for classes in a room heated above normal. The best-known version is Bikram yoga, a fixed sequence of 26 poses in a 90-minute class. Many studios now run their own heated flows with different poses, lengths and temperatures.

Heat, humidity and the fixed pace shape the experience. You sweat a lot, muscles feel looser, and the room can feel draining. Temperatures differ by studio, so ask for the room temperature, humidity and class length before you book rather than assuming.

Not every heated class is the same. Some are slow and gentle, some are fast and strong. Read the description, and ask whether the class is suitable for first-timers. For comparison, a non-heated flow class works the same poses at room temperature, and you can find both kinds on our Atlanta map by using the heated filter once it goes live.

How hard is a hot yoga class, really?

A study in a laboratory chamber at San Diego State University had 24 people complete a standardized 90-minute Bikram class while researchers measured oxygen use, heart rate and sweat. Average energy use was 286 kilocalories, ranging from 179 to 478, and every posture was rated light-to-moderate by American College of Sports Medicine standards (Pate and Buono).

Experience mattered. Heart rate averaged 72% of predicted maximum in novices and 86% in experienced practitioners. Sweat rate was about 0.6 kg per hour for novices and 1.1 kg per hour for experienced students.

The authors called claims of up to 1,000 calories per session unfounded. So heat makes the class feel hard, but it does not turn yoga into high-intensity exercise. If you want a heart-pumping workout, a hot room does not guarantee one.

What does heat do to your body?

In another study, 16 regular Bikram practitioners were monitored across a 90-minute session. Average heart rate was about 127 beats per minute, with a peak near 168. Diastolic blood pressure fell by about 10% on average, especially during floor postures near the end (Miranda Hurtado et al.). It was a small, uncontrolled pilot, so treat it as a clue and not as proof.

Why this matters: a drop in blood pressure and a high heart rate can feel like dizziness when you stand up quickly. The NCCIH states that hot yoga has special risks related to overheating and dehydration (NCCIH).

The NHS lists heat exhaustion symptoms as tiredness, dizziness, headache, nausea, heavy sweating with pale clammy skin, cramps, a high temperature and intense thirst (NHS). Knowing this list lets you act early.

How do you prepare for a hot class?

Start the day before: drink water regularly, not just in the hour before class. The NHS advises drinking more cold drinks when you are active or exercising, and wearing light, loose clothing (NHS).

Bring a large water bottle and a towel, and wear moisture-wicking clothing. The NHS also advises avoiding too much alcohol in hot conditions (NHS), so go easy the night before. Many people prefer a light meal two to three hours ahead, since an empty stomach or a big meal can both feel uncomfortable in the heat.

Arrive early so you can settle in and let your body adjust to the room, and place your mat near the door or a vent for your first visit. Tell the teacher it is your first heated class and ask what to do if you need a break.

After class, rehydrate with water, and eat something. If you sweat heavily, an electrolyte drink can help, as the NHS suggests an isotonic sports drink or oral rehydration powder for someone recovering from heat exhaustion (NHS).

Who should skip hot yoga or ask first?

Skip it, or get advice first, if you are pregnant, since both ACOG and the NCCIH say to avoid hot yoga during pregnancy because of overheating (ACOG; NCCIH). Our prenatal yoga guide covers safer options.

Check with a clinician if you have heart disease, high or low blood pressure, diabetes, kidney problems, a history of fainting, or take drugs that affect heart rate, fluids or temperature control. The NHS also advises checking on children, older people and people with long-term conditions, as they are more at risk of heat illness (NHS).

It is also sensible for healthy adults to skip a hot class when ill, feverish or short on fluids. The class will still be there next week, and a missed session costs you far less than heat illness would.

What to do if you feel unwell

Leave the heat as soon as you notice dizziness, nausea, a pounding headache or cramps. Tell the teacher, step outside, sit in a cool place, sip water and cool the skin with a damp cloth. The NHS steps are: move to a cool place, remove unnecessary clothing, drink water, cool the skin and stay with the person until they feel better, which should happen within 30 minutes (NHS).

Heatstroke is a medical emergency. Call emergency services (911 in the US) if symptoms include a very high temperature, hot skin that is not sweating, fast breathing and heartbeat, confusion, a seizure or loss of consciousness, or if the person is still unwell after 30 minutes of cooling (NHS).

Never push through these signs to finish the pose or the class. Resting in child’s pose is allowed in every studio, and leaving the room is allowed too.

Hot yoga versus non-heated yoga

Feature	Hot yoga	Non-heated yoga
Room	Heated, often humid	Room temperature
Feel	Sweaty, draining, muscles feel loose	Cooler, easier to focus
Main risk	Overheating and dehydration	Usual sprains and strains
Pregnancy	Avoid	Prenatal or modified classes
First-timer choice	Only after a few regular classes	Yes

Looser muscles in the heat can tempt you to go deeper than your joints are ready for. Move the same way you would at room temperature. If you want the benefits of yoga without the heat, a non-heated flow or hatha class is a sensible choice. Our first yoga class guide explains how to find one.

A simple plan for your first month

Take two or three non-heated classes first so you know the poses. Then try one heated beginner class, preferably mid-morning or early evening so you are not dehydrated from a long day. Stay near the door and do less than you think you can.

If it goes well, add one heated class a week. If you felt faint, queasy or wrung out afterward, go back to non-heated classes or try again in a cooler season.

Pair class with a short breathing practice at home to help you stay calm when the room feels intense. The breath coach offers paced breathing, and the pose atlas will show the shapes the teacher names.

Frequently asked questions

Is hot yoga good for weight loss?

A 90-minute class burned about 286 kilocalories on average in one lab study (Pate and Buono). Practiced regularly it can add to your activity, but it is not a shortcut.

How hot is a hot yoga room?

It varies by studio. Ask the studio for the posted temperature and humidity.

Can I do hot yoga if I am pregnant?

No. ACOG and the NCCIH both advise avoiding it (ACOG).

How much water should I drink?

Drink steadily through the day, bring water to class and sip as you need it, and follow your clinician’s advice if you have a condition.

How we checked this guide

Last checked 2026-11-07. We read the NCCIH yoga safety summary, the NHS heat exhaustion page, the ACOG exercise FAQ and the abstracts of two Bikram yoga studies. Studio temperatures vary, so confirm details with the studio. This is general education and not medical advice.