>>535463930
If the higgs field isn't in a true ground state, it would be in a higher energy metastable state around some equilibrium point - a false vacuum, and that means this quantum field could tunnel to the ground state (besides the field itself getting enough energy), changing the properties of quantum particles leading to fun things like atoms not being stable and annihilating us,
False vacuum decay has been experimentally tested, but we don't know if the universe's fields are in false vacuum state, however current measurements of particle masses do put us as likely to be in a false vacuum state, but there is wriggle room for us to be in the true vacuum.
https://www.nature.com/articles/s41567-023-02345-4
https://journals.aps.org/prd/abstract/10.1103/PhysRevD.97.056006

The decay would result in a localized region that expands at the speed of light and could start anywhere.
https://www.youtube.com/watch?v=gc4pxTjii9c
https://www.youtube.com/watch?v=zY6IK0ObDYU