Ad hoc teamwork aims to build learning agents, such as softbots or robots, that engage in cooperative tasks with other unknown agents. A typical assumption within the decision-making algorithms is to assume that the agent does rely on any predefined coordination strategy and communication protocols. Ad hoc teamwork with human teammates is one of the most promising topics within the multiagent research community; however, it largely remains unexplored. We envisage an exciting research work that explores the challenges posed by the collaborative interaction between robots and humans to build novel decision-making algorithms, which is HOTSPOT's fundamental goal.