As advanced weapon systems and future battlefields grow in scale, the importance of radars for detecting and defending against various aircraft and missiles is increasing. Containers used to supply power to radars for target surveillance and detection are mainly operated in open areas with few obstacles and high altitudes for extended periods of time. When exposed to sunlight, they are heavily affected by heat and ultraviolet rays, causing repeated expansion and contraction that can lead to a significant performance issue owing to cumulative fatigue loads on military equipment. Large structures like containers are complex and massive, limiting the feasibility of structural testing. Therefore, finite element analysis is performed to understand the impact of military equipment. In this study, the heat fatigue test method and engineering guidelines presented in Method 505.7 of MIL-STD-810H were referenced to confirm whether military equipment could withstand extreme temperature changes that might occur during its life cycle. Based on the finite element analysis results, fatigue life analysis was performed using the S–N curve and Minor's rule. The analysis results showed that the maximum stress occurred in the lower-right corner of the container frame, and a stress of 218.23 MPa was derived during the A1 cycle of MIL-STD-810H, indicating a fatigue life of approximately 60 years or 527,844 h, and infinite fatigue life was shown in the A2 cycle. In summary, the expected life of military equipment under periodic thermal stress could be estimated using the thermal fatigue calculation formula and MIL-STD-810H data.