Here are the most basic guidelines on how to use and take proper care of your baby mattress: • New mattresses need to be aired out for a few days before placing them in the crib so that when you put your kids to sleep, they won't be bothered by weird smells; • Babies need to sleep on their backs for safety concerns. Also, leave the mattress as it is without placing additional items on it such as covers, pillows, blankets, bumpers, or stuffed toys; • All crib mattresses must pass the well-known two-finger test - when you place your fingers between the mattress and the crib's sides, the space that's left shouldn't accommodate more than a maximum of two of your fingers; • Flip the mattress when the right time comes if you have a dual-sided one - till your baby is one year old, you should keep the firm side on, whereas toddlers can safely sleep on the softer side of the mattress; • Protect your mattress with a fitted sheet. You should even use waterproof pads under the sheet if your mattress isn't resistant to spills or liquids; • Read the instructions very carefully and if anything isn't clear enough, contact the manufacturer; • Store the mattress in a proper space that's cool and dry to avoid mildew. But, first, clean the mattress before putting it away; • After repeated use, some mattresses might lose their firmness, and indentations might occur, in which case you should replace the mattress.