The earliest undoubted evidence for the controlled use of fire by humans comes from sites no more than a million years old. Recently, however, very tentative evidence for the presence of fire has come from several Lower Pleistocene sites in Africa. A systematic approach to the problem of detecting and characterizing possible ancient fireplaces is clearly needed. The use of archaeometric techniques, particularly magnetic surveying and palaeomagnetism, may be crucial. Results from experimental and Holocene fireplaces in Australia are used here in an attempt to begin formulating an approach, and palaeomagnetic results from Lower Pleistocene sites in Africa are reviewed. -- AATA