The goal of this clinical trial is to compare the effect of high chlorine solution such as normal saline and non-high chlorine solution such as sodium lactate ringer's solution on renal function in patients with heat stroke. The main question it aims to answer is whether limiting the amount of normal saline infusion during emergency department can lower the incidence of acute kidney injury and mortality in patients with heat stroke. Participants will receive a free normal saline infusion during the emergency department according to the study design, or a restricted normal saline infusion while using sodium lactate Ringer's instead. Researchers will compare the normal saline infusion group and sodium lactate Ringer's group to see if limiting the amount of normal saline infusion during emergency department can lower the incidence of acute kidney injury and mortality in patients with heat stroke.