Despite the indication that the beneficial effects of hypobaric hypoxia preconditioning (HHP) in heatstroke are related to induction of heat shock protein (HSP) 70 in vital organs, there has not been any studies focusing on the relationships among HHP, brain HSP-70, and brain apoptosis, ischemia, inflammation, and oxidative stress in heatstroke. This study was to test whether HHP diminished apoptosis, ischemia, inflammation, and oxidative stress in heatstroke by up-regulating HSP-70. Anesthetized rats were randomly assigned to a) non-heated+non-HHP group, b) heated+non-HHP group, c) heated+HHP rats, and d) heated+HHP+HSP-70 antibodies (Ab) rats. All heated groups were exposed to heat stress (43 °C) , 70 minutes) to induce heat stroke. We reported here that HHP induced overexpression of brain HSP-70, which could be ameliorated by HSP-70 antibody treatment in rats. When anesthetized non-HHP (or without brain HSP-70 overexpression) rats, HHP (or with brain HSP-70 overexpression) rats, and HHP+HSP-70 Ab (or without brain HSP-70 overexpression) rats were exposed to heat stress, their survival time values were found to be 89-95 mins, 409-431 mins, and 99-113 mins, respectively. Compared to non-HHP rats or (HHP+HSP-70 antibody) rats, HHP rats displayed higher values of cerebral blood flow and partial pressure of oxygen. In contrast, HHP rats had lower values of apoptotic cells, cellular ischemia and damage markers, pro-inflammatory cytokines, oxidative damage markers, and an indicator for neutrophils accumulation in the brain. The beneficial effects of HHP in improving apoptosis, ischemia, inflammation, and oxidative stress in rat brain in heatstroke could be ameliorated by HSP-70 Ab therapy. These results suggest that HHP improved survival and prevented heat damage to the brain and that the underlying mechanism involved induction of HSP-70 and inhibition of ischemia, inflammation, oxidative stress, and apoptosis.