Aims Histamine interacts with the stress response in eukaryotes. This study investigated the effects of antihistamines on the heat shock (HS) response in yeast, thereby exploring their functions in a well-established histamine receptor (HxR)-free model. Methods and Results Stress response was evaluated by determining growth and viability of postlogarithmic phase grown yeast cultures after HS at 53 degrees C for 30 min. The effects of HxR ligands were investigated following short- and long-term administration. The H1R antagonist dimethindene exerted dose-related antifungal actions, whereas the H2R antagonist ranitidine failed to elicit any effect. In contrast, the H3/4R and H4R ligands, thioperamide and JNJ7777120, respectively, induced the thermotolerant phenotype. The circumvention of thermotolerance by cycloheximide and the induction of Hsp70 and Hsp104 expression indicated the contribution of de novo protein synthesis in the adaptive process, likely directed towards alterations in Hsp expression. Conclusions The data provide evidence for the differential function of HxR ligands in thermotolerance induction in yeast. Significance and Impact of the Study First demonstration of the action of antihistamines in the HS response in yeast. The work supports the potential HxR-independent functions of histaminergic compounds in fungal adaptation and stimulates research on the prospect of their exploitation in eukaryotic (patho)physiology.