A quick note about heat. Heat kills bacteria. Any process that heats your fermented foods higher than about 110 degrees risks killing the good bacteria you worked so hard to create. It is certainly fine to heat and eat fermented foods, you just lose the good bacteria. So enjoy it hot or cold, but remember to eat some that hasn’t been cooked.
If you are buying fermented foods that are not refrigerated, like jarred sauerkraut or pickles, they have been pasteurized (heated) to make it shelf-stable, and the good bacteria is all gone. More and more stores are now selling “live” sauerkraut and pickles, but you will find them in refrigerated sections.