So what goes into it? According to Bock, there are a lot of different layers, with the first being your basic genetic predispositions, which we can’t control.On top of that, there are the factors that we can control, like stress, diet, environmental toxins, and more. “I think stress is very important,” he says. “The value of the immune kettle is that, yes, frequently stress may be the largest component of the immune count.”Then you add in factors like allergies, sensitivities, hormone imbalances, and of course, big infections. “These are things that can really add layers to the immune kettle. And the key is that these layers can be different sizes,” he explains. “So if they’re small, they’re low. The lower you reside in the immune kettle.”Importantly, Bock notes that, depending on how well you handle stress, it could be the very factor that puts you over the edge, to your kettle’s boiling point. An overload of stress, he says, is what increases many people’s susceptibility to illness.