The Fermzilla 30L Insulated Jacket is designed to keep your Fermzilla at the optimal fermenting temperature all year round. The jacket also blocks out light to prevent light struck or skunked beer.
To heat it is recommended you use a temperature controller with a heat mat. To cool you can simply add a frozen bottle of water underneath the jacket.
For cooling you can also simply freeze some bottles of water then put them into the insulated bag and this will effectively cool down the fermenter.