The skin which covers my body is the largest organ that I have. Human skin is porous and functions as a bidirectional membrane. Contrary to some animals, humans can’t really exchange Oxygen and Carbon-diOxide through their skin. Instead, our skin has external touch receptors, which feed our brain information on physical contact.
A random fly landing on my body or a hair coincidentally touching my skin are examples of gentle external touch sensations. Sometimes similar sensations arise without any external stimulation. When sitting with closed eyes, it isn’t easy for me to distinguish if the cause is internal or external.
When holding or accelerating my breathing for a long while, bloodstream gasses swing out of balance, and these swings may trigger skin sensations without external stimulation.
I can manipulate my breathing to feel a temperature change. For example, when holding my breath and entering my discomfort zone, I usually sense a rise in skin temperature. When I get to diaphragmatic convulsions, the heating intensifies. When hyperventilating, I may feel skin tingling and other ‘funny’ effects on my skin.
By getting to know the nature of the sensations that breath-holding and hyperventilating trigger in my body, I can get essential indications of my breathing.