The article provides a recapitulation of published data on plant cellular response to high temperature stress. We have reviewed the main stages of this response: heat sensing and signal transduction and synthesis of heat shock proteins (HSP). Some structures and components of plant cells, which are the most probable participants of heat sensing, are described. An emphasis is placed on plasmalemma, calcium channels and calcium ions. The hypothesis of the participation of cytoskeleton, phytochrome B, HSP70 and HSP90 is also considered. Another idea of the article is possible participation of secondary stress, for example ER-stress, in heat sensing and signaling. It is shown that calcium ions and reactive oxygen species (ROS) are components of the heat sigaling pathway. Additionally, calcium-binding proteins, lipid signaling molecules, phytohormones and transcription factors (HSF, MBF1, DREB, C2H2 ZF) can participate in signal transduction pathways induced by high temperature. The article stresses a particular role of heat shock proteins (HSPs) in plant response to heat stress. Five major groups of HSP (HSP100, HSP90, HSP70, HSP60, sHSP) are taken into consideration. Sensing of heat, heat signal transduction pathways and synthesis of HSP are the main events in the process of plant cellular response to high temperature stress. The final result of these events and other temperature-dependent changes in plants is enhanced thermotolerance of plant cells and whole plants that lead to higher plant survival under high temperature stress.