In the altitude region between 350 and 550 km, variations in the ion temperature principally reflect similar variations in the local frictional heating produced by a velocity difference between the ions and the neutrals. Here we show the distribution of the ion temperature in this altitude region and discuss its attributes in relation to previous work on local Joule heating rates. In addition to the ion temperature, instrumentation on the DE 2 satellite also provides a measure of the ion velocity vector representative of the total electric field. From this information we derive the local Joule heating rate. From an estimate of the height-integrated Pedersen conductivity it is also possible to estimate the global (height-integrated) Joule heat rate. Here we describe the differences and relationships between these various parameters. ¿ American Geophysical Union 1988