We know that the human body responds to changes in the weather. The question is how does it measure these changes? What are the receptors that our body relies on to alter its internal milieu to suit external circumstances, and where are they situated? Some answers are obvious, forinstance: You can tell wind direction by licking a finger and holding it up in the air. You can tell if a piece of clothing that comes out of the drier is dry or just cold by holding it against your lips. You know its sunny because...well because your eyes and skin tell you so. And some answers are not so clear. e.g. How does our body estimate humidity? How does it compensate for changes in pressure, and do so without us realizing it? Receptors may well be in the most unlikely places. I just read an article which says that researchers have found receptors in lung sensitive to BITTERNESS. ? A whole host of questions come to mind, such as what purpose could that serve? Where does that information get relayed to? What happens if the receptors read excess bitterness, or too little? Why does the lung need to know? Over to you. John Bart.