Two problems with wood floors, buckling or cupping. Buckling is high humidity on both sides of the wood which expands the wood dramatically. Reduce the humidity to less than 50% on both sides of the floor and it will return to it's original size in few weeks. This may leave cracks.
Cupping is being high relative humidity on the cup away from side. Equalizing the % RH on both side will return the wood to a flat lie. Heating during winter and dehumidification during the summer are methods of controlling relative humidity. Check for a wet crawlspace if the floor is on a crawlspace. Crawlspaces should be less than 60%RH to prevent cupping and mold growth.