Being healthy helps, but assuming you are tired/stressed, there's still ways to stay in control. 1) You have to recognize that you're nearing red zone, i.e. no

Being healthy helps, but assuming you are tired/stressed, there's still ways to stay in control. 1) You have to recognize that you're nearing red zone, i.e. notice the physical effects of the adrenaline rush. If you can't consciously notice it happening and intervene, then you're just a meat puppet to your emotional system. You may notice that it causes you to breathe rapidly, for example. Don't worry about step 2 until you've got this part down. 2) Once you can notice it, you have to do the mental gymnastics in the moment to convince yourself that you're not going to do anybody any favors by indulging your emotion. If you've resolved ahead of time that you want to get on top of it, that's a good start; in the moment you need to remember that resolution and stick to it. 3) Be aware that you're possibly not going to be able to calm down instantly (though a physical trick that helps is to take two or three deep breaths through the nose). In a situation like this, you'll have chemicals running through your blood that keep wanting to short circuit your rational thinking. Either try to change the subject, propose to "agree to disagree" for now until you can think about it some more in your own time, or if possible try to end the conversation politely. It'll be very hard to continue to keep talking calmly about the subject that triggered you if you've got a strong emotional response (although with practice it is doable.) You can also discuss ahead of time with your spouse/partner, tell him/her that you're working on this, and that sometimes you'd like their permission to put conversations on hold until you're in a better frame of mind - just don't abuse their willingness, and make sure not to use it as an excuse for avoiding difficult topics.