1. Warnings

You should never get out of breath, feel tired or feel as if you are straining yourself, when practising Yoga Asanas or Pranayama.

Do not practice asanas between 12 noon and 1 p.m. The sun is at its zenith and the body may get easily over heated. You should stop doing asanas at 12 noon. Pranayama, however, can be practised between 12 noon and 1 p.m.

Pranayama can be practised a maximum of four times a day: at sunrise, noon, sunset and at midnight. Yet, once a day, or whenever you have time, is fine.

You should keep cool and never over-do yourself, especially if you are over 40 years of age.

Do not practice yoga in the wind of an electric fan, or in an air-conditioned room. You can easily catch a cold.

Do not shower, bathe or immerse the body in water, right after practising yoga asanas or pranayama. You may catch pneumonia. 
You should wait at least 45 minutes. If you feel uncomfortably hot and sticky, you can wipe the body with a damp cloth.