Oil tank covers can become hot depending on the tank cover's construction and amount of heat exposure. For example, oil tank covers made from steel might easily become hot, while oil tank covers made from Dura-Vinyl do not heat as easily.
Oil tank covers made from steel conduct heat quickly, as metals easily conduct heat and other energy. Therefore, if a steel oil tank cover is left out in particularly hot sun for long periods of time or exposed to heat from the oil tank, it may become hot. Dura-Vinyl oil tank covers can get hot but not as quickly as steel covers.