If liquid is spilled on your mattress, blot up the spill immediately, being careful not to push the liquid further into the mattress. Cover the damp area with either clean kitty litter or baking soda and let it sit for two to three hours. Kitty litter and baking soda are absorbent so they will pull the excess moisture out from inside the mattress as well as eliminate any lingering odors. When the mattress is dry, vacuum up the kitty litter or baking soda.
If you have time, turn your hair dryer to the low setting. Hold the hair dryer at least an inch over the dampened area and keep it moving so it doesn't warm one area for too long. Keep the hair dryer moving around the area until it is completely dry.
Open the windows and place a fan nearby to circulate air over the area.
Take the mattress outside to sit in the sunshine. Make sure that the damp area is facing up. Place a blanket or tarp underneath the mattress to keep it from getting dirty. Sunshine is great not only for drying the mattress, but for killing any germs and bacteria and for reducing lingering odors. The earlier in the day you do this, the better chance it will have of getting dry. Do not leave the mattress outside overnight; it may accumulate more moisture in the early morning.
If the mattress has been thoroughly soaked in a flood, drying it out may not be the best option. A mattress that has been wet for 24 to 48 hours could already have mold in it. Look in the phone book under "water damage restoration" or "flood" to find a professional.
Do not store or put bedding on a wet mattress; it will accumulate mold. Make sure that the mattress is completely dry before using or storing it.