How can a breathing exercise cool me down?

Techniques like Sitali breath involve breathing in through a curled tongue, which cools the air and can help lower your body temperature.

Is this safe to do in winter?

It's generally safe, but it's most beneficial and comfortable to practice in warmer environments.

Is this a substitute for medical advice?

No. The information provided is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.