The Internet of Bio-Nano Things (IoBNT) is a new type of communication network, which aims to bridge the gap between classical electromagnetic communications and the biological world, especially the human body. The establishment of such a system promises transformative breakthroughs in disciplines like information technology, pharmacology and medicine. However, before this concept becomes reality, a number of challenges need to be addressed. In this work, we address the two most important ones: bio-compatibility and electrical interfaces. We propose a novel thermomolecular communication interface, which allows data transmission through the human skin by generating variations in the temperature. Importantly, our concept realizes this transmission, without damaging this critical protective layer of the organism. Furthermore, we present a novel micro/nano-scale receiver, which is based on the Arrhenius principle and converts temperature variations into a molecular signal. Thus, our approach is compatible with existing IoBNT communication schemes, especially Molecular Communications (MC). We provide a detailed physical and control theoretical model of the proposed thermomolecular system and evaluate the system dynamics, noise behavior and error performance via computer simulations.