How to Use Multi Sig and Cold Storage for NEM?

Hello Everyone,

I am new to NEM and still learning. I have enabled Harvesting but I am really not how to secure my Nano Wallet since it is always online on my PC. Can some one please help me with a link or video to know more about Multisig and how to enable that. In addition, I would love to know more about Cold Wallet and if Harvesting is possible using Cold Wallet ?

Greatly appreciate your response.
Thanks
Dom

Maybe you should think about buying Trezor wallet?