Tummo is one of the integral part of Tibetan Buddhism. Here are some explanations from
http://pinto2011.hubpages.com/hub/tummo-meditation-techniqueTummo is an ancient Tibetan monk meditation technique, a type of tantric yoga, residing in the Himalayas where they increase the temperature of their body up to 17 degrees. They do it to burn the thousands of evil thoughts which crosses our mind and redirect the thought process to constructive one. They practice it by drying three wet clothes placed in their bare body with outside freezing temperature.
WHO THESE PEOPLE ARE WHO PRACTICES THIS MEDITATION TECHNIQUE:In the Kagyu Tradition of Buddhism (Tibetan), there are six types of Yogas of Naropa and Tummo is one of them. It is the meditation of inner heat and it is practiced to control the subtle body and perform the higher yogas and this tantric yoga is practiced in Tibet by the Buddhist monk.
WHY TUMMO MEDITATION TECHNIQUE IS PRACTICED:This Tummo meditation is based on the ancient tantric teachings and the teachings are based on the common belief that we as a human beings are born with free flowing energy and we waste it by worrying about different sorts of things in our daily life. So, instead of worrying Tummo meditation is practiced to concentrate and burn all those worrying thoughts and keep our mind and body healthy. So, it is basically channelize all those worrying energy into productive ones.
HOW TUMMO MEDITATION TECHNIQUE IS PRACTICED:Tummo is basically a breathing technique. We need to sit in a mat with your legs crossed over one another and with your hands placed over the knees. Then close your eyes, try to concentrate by kicking out all the thoughts out of your minds which are emerging from various directions. When we breath, the noticeable movements happens in our bowel, i.e., it comes up and down. So, concentrate on the movement of the bowel during the inhaling and exhaling periods. Slowly then start coming up and concentrate on your nose and feel the breath while inhaling and exhaling. Once you are able to concentrate without any straying thoughts, imagine your body as a hollow balloon and visualize that a hot lamp is placed at the center of that hollow balloon discharging heat. Slowly, your body will start heating up.
NOTE: IT WILL TAKE TIME STILL YOU MASTER THIS TANTRIC TECHNIQUE AND START GENERATING HEAT.
LIVE EXAMPLE OF THIS TUMMO MEDITATION TECHNIQUE:There is a man named Wim Hof got the nickname if Iceman for his extreme capacity of bearing with cold. He first ran barefooted in the Artic and has now aimed for the Antartica. He has 18 world records in his name from bearing different kinds of cold including longest ice bath by staying immersed in ice for 1 hour, 13 minutes, and 48 seconds. He often challenges his body to the extreme when it comes to bear cold. He attempted to climb mount Everest by wearing only shorts and nothing else. He has proven the world that with Tummo meditation and practicing it religiously and judiciously one can do the unimaginable.
WHAT ARE THE HEALTH BENEFITS OF THIS KIND OF TUMMO MEDITATION: There are multiple benefits of doing Tummo meditation:
1. It gives you unimaginable power to fight with cold as Iceman has proven.
2. It is said that it clears any kind of plaques forms inside our artery or vein, that is it keeps our heart healthy.
3. Being basically a breathing technique, it keeps our lungs healthy.
4. It improves concentration.
5. It improves memory power.
3. It makes your more calm and composed besides other health benefits of being yoga.