Networks of implanted biomedical sensor nodes promise to give a new direction to medical research. The in vivo sensor nodes collect desired biometric data and communicate the data wirelessly to a base-station through a multi-hop network. The wireless communication produces heat, leading to a rise in the temperature of the nodes. A high temperature of the in vivo nodes for a prolonged period is not desired as it might damage the surrounding tissues. Medical applications are also often delay-sensitive. In this paper, we propose Hotspot Preventing Routing (HPR) algorithm that performs much better than the shortest hop routing algorithm and the previously proposed Thermal Aware Routing Algorithm (TARA) in terms of preventing the formation of hotspots and reducing the average packet delivery delay by dynamically adapting to the network load. The simulation results presented also show that the HPR algorithm is highly scalable, increases the operational life of the network and helps reduce the number of packets dropped.