In this work, a multi-modal pain intensity recognition system based on both audio and video channels is presented. The system is assessed on a newly recorded dataset consisting of several individuals, each subjected to 3 gradually increasing levels of painful heat stimuli under controlled conditions. The assessment of the dataset consists of the extraction of a multitude of features from each modality, followed by an evaluation of the discriminative power of each extracted feature set. Finally, several fusion architectures, involving early and late fusion, are assessed. The temporal availability of the audio channel is taken in consideration during the assessment of the fusion architectures.