The present disclosure relates to a heat exchanger, for example an indirect charge air cooler for an internal combustion engine. The heat exchanger includes a heat exchanger block including a first channel system for a first fluid and a second channel system for a second fluid that is fluidically separate from the first channel system. Two opposite side parts and two opposite end parts are structured and arranged to fluidically delimit the second channel system. At least one frame part is connected with a respective edge of the two side parts and of the two end parts. An air inlet box is connected to the at least one frame part via a seal. The heat exchanger block has a width b1 and a height h1, and the seal has a width b2 and a height h2, where b1≥b2 and h1≥h2.