Ectotherms can regulate their body temperature by moving between cooler and warmer environments. The choice of a thermal environment can be driven by different parameters, including an individual’s health status. For instance, disease and parasite infection can cause some species of fish to increase their body temperature by spending more time in warmer waters, presumably to maximise their immune defences and, thus, the chance to fight off the infection, a phenomenon known as behavioural fever. Most studies on fish thermoregulation do not consider how the immune response to disease and/or parasite infection can shape a fish’s thermal choice. Yet, the severity of the parasite infection (load), the presence of multiple parasite species (co-infection) and the timing of the infection (acute vs. chronic) can change temperature preference. Here, we measured the preferred temperature of wild-caught pumpkinseed sunfish using a shuttle-box system. Fish were separated into three groups: 1) chronically co-infected by parasite, 2) acutely exposed to parasite, and 3) immune-stimulated via injection of lipopolysaccharide (LPS) endotoxin. We observed that the fish’s preferred temperature did not vary with parasite infection,co-infection and immune-stimulation. This suggests that fish did not display behavioural fever. This combination of groups with different infection status allowed us to tease apart the role of the immune system in thermal choice and deepen our understanding of animal movement. Ultimately, this helps our comprehension of how ectotherms fight disease in nature.