Abstract: At present, the power grid company has a number of 35kV board room (box-type) substation, its maintenance space is small, poor ventilation, poor heat dissipation effect, often open the sauna mode in the summer, staff to carry out work, often because the protection is not in place personnel heat stroke events. Starting from the pathology and harm of heat stroke, according to the special environment of Banfang substation, combined with the vision of "intrinsic safety" of enterprises and the summary of on-site practical experience, this paper extracts several effective preventive measures from the four aspects of "human, material, environment and pipe", and also summarizes the treatment measures when heat stroke occurs.