Metamaterial absorbers (MAs) play an important role in stealth technology in microwave bands. Although MAs absorb incident RF power, they usually convert it into the heat which might be a disadvantage for counter-measurement against remote thermal imaging systems. In this study, we present the design, simulation, fabrication and RF/thermal imaging of a narrowband MA in the microwave region. The MA consists of a two dimensional periodic array of a well-known metallic split ring resonator (SRR) and a ground plane separated by a dielectric layer. For horizontally and vertically polarized illumination cases, thermal imaging of the MA is carried out using a commercial thermal imager which has a longwave infrared sensor between 8–12 µm wavelengths. Surface temperature map of the MAs are extracted from the recorded thermal images. It is shown that a slight temperature difference happens with respect to the ambient temperature for the MA of the near-perfect absorption whereas the MA of the near-zero absorption has zero temperature difference. Physical mechanisms of the RF absorption and the RF induced heat loss are explained using further electromagnetic numerical simulations.