A standard Bikram yoga class is held in a room heated to 105°F (40°C) with 40 percent humidity. That combination of heat and moisture makes the room feel significantly hotter than the thermostat reading alone would suggest, and it’s what separates Bikram from most other styles of yoga.
The Standard Room Conditions
Every certified Bikram class follows the same environmental recipe: 104 to 105°F with humidity locked at 40 percent. These conditions aren’t suggestions. Studios that teach the official Bikram sequence maintain these numbers throughout the full 90-minute session. The humidity prevents sweat from evaporating efficiently, which is why you’ll be drenched within the first few postures even if you’re in good shape.
For context, 105°F is hotter than the hottest day most people in the U.S. will ever experience outdoors. The difference indoors is that there’s no breeze, no shade, and no escape from the heat while you’re holding poses.
What Happens to Your Body Temperature
The room is 105°F, but what matters more is what happens inside your body. A study sponsored by the American Council on Exercise had 20 experienced Bikram practitioners swallow core body temperature sensors before completing a full 90-minute class. By the end of the session, men’s core temperatures averaged 103.2°F and women’s averaged 102.0°F. One male participant hit 104.1°F, and seven of the 20 subjects exceeded 103°F.
A normal resting core temperature is around 98.6°F. Medical professionals generally consider anything above 104°F to be the danger zone for heat-related illness. So while most practitioners stayed below that threshold, some came close. The fact that experienced yogis, not beginners, were the ones measured makes this especially worth noting. If you’re new to Bikram, your body hasn’t yet adapted to managing heat during intense physical effort, and your core temperature could climb higher.
What a Class Looks Like
Bikram follows a fixed sequence of 26 postures and two breathing exercises, performed in the same order every time. Each posture is done twice (with the exception of the final spinal twist), and the full session lasts 90 minutes. The class opens with a standing deep breathing exercise and closes with a rapid exhale breathing technique. There’s no music, no variation, and no flowing from pose to pose the way you would in a vinyasa class. You hold each posture, rest briefly, then repeat it.
The fixed structure means there’s nowhere to hide. You can’t skip the harder poses or move at your own pace. Combined with the heat, this makes Bikram one of the more physically demanding styles of yoga, even though many of the individual postures aren’t especially advanced.
How Many Calories It Actually Burns
One common claim is that a single Bikram session burns 1,000 calories. Research from Colorado State University tested this directly and found the real numbers are considerably lower: about 460 calories for men and 330 calories for women per 90-minute class. That’s roughly comparable to a brisk walk for the same duration. The inflated calorie estimates likely come from the perception of effort. You feel like you’re working extremely hard because of the heat, but much of that sensation comes from your body trying to cool itself rather than from muscular exertion.
How Bikram Compares to Other Hot Yoga
“Hot yoga” is a broad category, and not all heated classes are as intense as Bikram. Many studios offer heated vinyasa or power yoga classes in rooms set between 85°F and 95°F, which is noticeably warm but 10 to 20 degrees cooler than a Bikram studio. Some franchise studios teach a modified version of the Bikram sequence at slightly lower temperatures with a less rigid format. If you’ve taken a generic “hot yoga” class and found it manageable, Bikram at its official temperature will feel like a significant step up.
Staying Safe in the Heat
The biggest risks in a 105°F room are dehydration, heat exhaustion, and in rare cases, heat stroke. You’ll lose a substantial amount of fluid through sweat during 90 minutes in that environment, and with it, electrolytes like sodium and potassium that your muscles and nervous system depend on. Drinking plain water alone may not be enough. Adding an electrolyte drink or eating a sodium-rich snack before class helps your body retain the fluid you take in.
Hydration should start well before class. If you walk into a heated room already slightly dehydrated, you’ll hit a deficit quickly. Signs that you’re in trouble include dizziness, nausea, confusion, or a sudden stop in sweating despite the heat. If any of these happen, leave the room and cool down. Studios keep the door closed to maintain temperature, but you’re always allowed to step out.
Pregnant women should avoid Bikram entirely. Elevated core body temperature during pregnancy poses risks to fetal development, and the heat also loosens ligaments beyond what’s safe, increasing the chance of joint injury. Harvard Health Publishing notes there are currently no studies confirming heated yoga is safe during pregnancy, and the known effects of raised core temperature are reason enough to choose an unheated practice instead.
People with heart conditions or blood pressure issues should also be cautious. The combination of heat, humidity, and physical exertion forces the cardiovascular system to work significantly harder than it would in a room-temperature class.