Abstract Background Temperature extremes represent an important limiting factor to plant growth and productivity. The present study evaluated the effect of hydroponic pretreatment of strawberry ( Fragaria x ananassa cv. ‘Camarosa’) roots with an H 2 S donor, sodium hydrosulfide (NaHS; 100 μM for 48 h), on the response of plants to acute heat shock treatment (42°C, 8 h). Results Heat stress-induced phenotypic damage was ameliorated in NaHS-pretreated plants, which managed to preserve higher maximum photochemical PSII quantum yields than stressed plants. Apparent mitigating effects of H 2 S pretreatment were registered regarding oxidative and nitrosative secondary stress, since malondialdehyde (MDA), H 2 O 2 and nitric oxide (NO) were quantified in lower amounts than in heat-stressed plants. In addition, NaHS pretreatment preserved ascorbate/glutathione homeostasis, as evidenced by lower ASC and GSH pool redox disturbances and enhanced transcription of ASC ( GDH) and GSH biosynthetic enzymes ( GS, GCS ), 8 h after heat stress imposition. Furthermore, NaHS root pretreatment resulted in induction of gene expression levels of an array of protective molecules, such as enzymatic antioxidants ( cAPX, CAT, MnSOD, GR ), heat shock proteins ( HSP70, HSP80, HSP90 ) and aquaporins ( PIP ). Conclusion Overall, we propose that H 2 S root pretreatment activates a coordinated network of heat shock defense-related pathways at a transcriptional level and systemically protects strawberry plants from heat shock-induced damage.