Hi
Mobile homes are renowned for being difficult to keep comfortable. (I lived in one for 4 years, and I fitted an AC unit designed for a small computer room) You could dig a hole insulate it, fill it with rocks, put a lid on it, and duct the air down into it. Then on a cool evening you could return the air from round the warm rocks back into the mobile home. Depending on the temperature of the scavenged heat you could put it into stored water, air to water heat exchangers are easy to come by, car radiators. Without doing tests and measurements so you know exactly how much heat there is. Like wind because it feels like a good blow doesn't mean it is, likewise because it feels uncomfortable to your body doesn't mean there is enough waste heat to do anything with, apart from getting you to sweat a bit.
Brian