Objective To discuss the role of medical protection patterns in preventing exertional heat stroke during 5-km armed field examination in summer. Methods We analyzed the original data collected from 501 soldiers who completed the 5-km armed field examination in the summer of 2016. The soldiers received medical protection during examination and were divided into fully-equipped group (loading 9-12 kg, n=270) and non-equipped group (n=231). The temperatures of the soldiers were detected before and after examination, and the temperature changes and the number of soldiers with hyperthermia after examination were compared between the two groups. Results A total of 501 soldiers took part in the 5-km armed field examination, and 51 (10.18%) soldiers were found with fever (temperature >37℃), with a highest temperature of 40.9℃. Nine were put on a temporary stay in the field medical facility. Among them, four were observed because of the temperature maintaining at 38℃ for 15 min, and their temperatures dropped to below 37℃ after cooling fluid infusion for 50-120 min; four were observed because of chest tightness, suffocation, and abdominal pain; one was observed because of faint; the latter five cases were improved without other treatments. No case was evacuated to the hospital. There was no significant difference in temperature between the fully-equipped and non-equipped groups before the examination, while the temperature in the fully-equipped group was significantly higher than that in the non-equipped group after the examination ([36.64±0.67]℃ vs [36.48±0.38]℃, P<0.05). The number of soldiers with hyperthermia in the fully-equipped group was significantly more than that in the non-equipped group after the examination (16.67%[45/270] vs 2.60%[6/231], P<0.05). Conclusion The 5-km armed field examination in summer can elevate temperatures of the soldiers and has risk of inducing heat stroke. Establishing a targeted medical protection pattern during the examination may help to timely detect fever in the soldiers and give prompt treatment, so as to effectively prevent heat stroke.