The 5th International Conference on Heat Transfer and Fluid Flow (HTFF'18) aims to become the leading annual conference in fields related to heat transfer and fluid flow. The goal of HTFF'18 is to gather scholars from all over the world to present advances in the relevant fields and to foster an environment conducive to exchanging ideas and information. This conference will also provide an ideal environment to develop new collaborations and meet experts on the fundamentals, applications, and products of the mentioned fields. HTFF is an acronym for Heat Transfer and Fluid Flow.