There are some circumstances where a freestanding dehumidifier would help. Suppose you live in an airtight corrugated iron hut. In shade. With 100% humidity. Your air inside is at ambient temperature. You run the dehumidifier, and the air gets hotter and dryer. The heat can easily conduct out through the walls, but the dryness stays. So soon your room is full of near ambient temperature dry air. So sweating can cool you.
There are some circumstances where a freestanding dehumidifier would help. Suppose you live in an airtight corrugated iron hut. In shade. With 100% humidity. Your air inside is at ambient temperature. You run the dehumidifier, and the air gets hotter and dryer. The heat can easily conduct out through the walls, but the dryness stays. So soon your room is full of near ambient temperature dry air. So sweating can cool you.