Man can only tolerate a limited range of environmental conditions, whereas other lifeforms thrive in the most intense conditions - in extreme heat or many, many leagues under the sea in utter darkness or deep in the middle of rocks. Why is this so?

Can someone really die of fright? How do cocaine, LSD and morphine work? Why do chilli peppers taste hot? This book reveals the secrets of ion channels, which produce the electrical signals in our cells.