Why a tank can hold on to heat
A tank’s steel armor does not simply block the sun; it absorbs sunlight and carries some of that energy inward. The warmed inner surfaces then heat the air and anything touching them. In a cramped crew compartment, there is little room for hot air to disperse, and the crew, radios, displays, and other equipment add still more heat.
Ventilation has limits
Fans and vents can move hot air out, but they cannot always keep up with intense sun and heat generated by the vehicle. Ventilation also has to work with filters and protective systems that limit what enters the crew space. In some tanks, heat from the engine and transmission can warm nearby floors or partitions, although the layout and degree of isolation vary by vehicle.
Unlike a car, a tank may have no effective air conditioning—or may have cooling designed chiefly for equipment rather than crew comfort. The result is a slow buildup: hot armor keeps radiating heat even after the sun shifts, while the enclosed space sheds warmth poorly. The same armor that protects the crew can become a broad, heated surface surrounding them. That makes shade, airflow, and time spent inside matter as much as the temperature outside.
