Because hybrid mattresses combine innerspring and foam systems, they might take longer to break in – between 30 and 90 days. Don’t walk on the mattress to avoid damaging its coils if you want to speed up a break-in. Instead, roll or crawl over the foam layers.  When breaking in a new hybrid mattress, let it breathe before removing it from its packaging. Especially if your mattress comes packaged in a box, the layers of foam may take a while to expand fully. In addition, you should always place your mattress on a sturdy foundation, so pick a frame carefully.  Finally, consider turning up the heat for the first few days. Doing this can help soften traditional memory foam.