In an age where the phrase “climate change” can no longer be ignored, we (scientists) are expected to know if and how global warming will change the world we live in. There are so many papers that predict dramatic ecological changes based on organismal responses to climatic projections; and much of those prediction are about species extinctions and range shifts. A closer look at some of these papers quickly reveal that we have forgotten our basics: the physics and physiology of thermal adaptation. I will take us quickly through a lesson in thermal biology of ectotherms and then together, we can critically look at some of the global analyses of predicted lizard extinctions (that are simply rubbish).