Graco P&P bassinet too cold for newborn?

Hey everyone. So this is the set up we have for my almost 3 week old. For those that aren't familiar, it's the Graco Play-yard / Pack n Play with an extra bassinet area that sits higher up. Underneath there is a big empty space. Every morning, my baby wakes up with cold hands and feet. I have him in a Halo sleep sack now with a receiving blanket stuffed in the bottom, socks, onesie, warm jammies, mittens, and a hat. He's had a slight cold for a couple days and I'm afraid being cold like that will make him more sick. Any ideas as to what I can do to make him warmer without adding unsafe blankets and such to the bed? We keep the house warm at night, too. Thanks!