I need to cool down...
For whatever reasons, you're feeling so upset with someone (usually important to you) that you're aware that you're not currently resourceful enough to do anything more than worsen the situation if you continue to engage with them now. That might also be true for them, but it's best not to mention that.
"It's important for me to work this out with you, but before I'll be able to respond non-defensively and helpfully, I need to cool down. I hope you understand. I'm going to leave now so I can calm down. I promise I'll let you know when I'm ready to talk with you again so that we can make this okay between us. I'll check to see if you're ready also."
My client Stuart found himself feeling hurt and defensive when, after everything he'd already done to try to make his girlfriend Jean happy, she was once again complaining about how he didn't make enough time for her.
He managed to observe himself again falling into one of those mutually hurtful and non-productive quarrels that made him question his relationship with her, even though he deeply loved her. And he also remembered my coaching suggestion when we had previously dissected a similar spat.
Taking a deep breath, in a conciliatory tone, he said,
"Jean, I'm sorry for what I just said. I said it because I got defensive with you. I need to cool down. I hope you understand. I'm going to go away now and I'll come back later when I know that I can listen to you without getting defensive."
About an hour later, after Stuart was able to cool down and get in touch with his desire to have great relationship with Jean, he invited her to have a partnership conversation so that he could understand how she was feeling and seeing things and find a way for them both to be happy regarding this issue. She agreed.
In some circumstances, it might not be so much your defensiveness but that of your cohort that would present the danger in continuing the conversation at the current time. Yet, it's not likely to go over well if you say, "You should go cool down first." Therefore, even though a cool down period might not be so necessary for you, it could be best for your relationship if you ask for a cool down period for yourself, not mentioning that they probably need it too. This will also give you more time to come up with a better approach to re-enter the conversation later than you might have if you continued at the current time.