Remove the bedsheets and pillows. Carefully lift up each corner of the mattress pad to remove it from the mattress.
Gently shake out the mattress pad to remove any large particles of debris that may be caught in the fabric.
Insert the mattress pad into the washer. If the washer is large enough, place the pad in with the bedsheets and pillowcases.
Set the washer to the "Warm Water" setting. Measure out and pour in a half cup of laundry detergent. Set the washer to "Normal" or "Permanent Press" cycle, then press "Start" or "Power." Allow the full cycle to complete.
Remove the mattress pad from the washer and place in the dryer. Set the dryer to "Warm" or "Medium Heat." If available, set the timer to 60 minutes. Press "Start" or "Power" to begin the drying cycle. After the cycle has ended, check the pad. If it is still wet, run it for another cycle or hang it up to air dry.