Infrared thermography (IR) has proven to be an effective alternative method for determining room temperature within buildings. Nevertheless, IR is limited to surface temperature measurements, as opposed to direct indoor air temperature measurements, and it is not free from errors (emissivity, camera calibration, poor focus, etc.). Therefore, IR tends to be used to obtain qualitative rather than quantitative data. The main contribution of our study is the development of a technique that produces precise quantitative measurements in building interiors and structures using thermal cameras. A low-cost, portable measuring screen system has been developed for this purpose, and its high precision level has been confirmed after overcoming problems related to emissivity, focus, and reflected temperature. The technique is versatile and can be applied in a multitude of settings to obtain quantitative measurements of the air temperature distribution in the interior of buildings. (C) 2013 Elsevier B.V. All rights reserved.