Poke completely through the center of the bubble, using a sewing needle that is large enough to allow the trapped air inside the bubble to escape.
Drape a towel over the bubble and press down. Plug in a clothes iron and allow it to heat. Iron the towel on top of the bubble to loosen any glue inside the bubble, so that it now sticks to the floor underneath.
Remove the towel and place a thick book on top of the spot. Fill a gallon bucket with water and place it on top of the book. Allow it to sit for 24 hours.
Remove the bucket of water and the book. Check to see if the bubbled area of flooring now adheres to the floor.
Insert the tip of an adhesive flooring repair syringe through the needle hole in the bubble if the spot does not stay down. Squeeze two or three drops of glue out of the syringe into the bubble, or use the amount recommended by the manufacturer.
Cover the bubble with a piece of wax paper. Place the book and bucket of water on top of the bubble. Let the glue dry according to the syringe manufacturer's instructions.