Distilling his great reference work Hot-Blooded Insects, Heinrich, in his ever engaging prose style, explains how, when, and in general what insects regulate their body temperature and what it means to them. As he shows us, the ingenuity of the survival strategies insects have evolved is astonishing: from shivering and backing, the construction of turrets, cooling with liquid faeces to `panting', `sweating', and counter and alternating currents of blood flow for heat retention and heat loss.