Warmth dilates your blood vessels, which increases your range of motion, says Kay Kay Clivio, senior manager of yoga experience for Equinox in New York City.
But hotter isn’t always better: Research shows that in order to avoid negative side effects, you should never practice in temps higher than 95 degrees. Past that point, the heat adds nothing to your practice from a form perspective. Instead, it just ups your chances of dehydration, heat exhaustion, overstretching, and pulling or straining a muscle.
The bottom line:
Skip classes that are held in rooms kept at or above 95 degrees. All of Equinox’s offerings, including Heated Vinyasa Yoga and the yet-to-launch Signature Heated, stay within the safe 85- to 90-degree range.