Toxic relationships tend to build slowly. You can often can see them coming from a mile away--a passive-aggressive email here, an eye-roll there. Yet, we can all get caught off guard when emotions boil over.

That's because in the face of interpersonal conflict, many managers will stick their head in the sand, complain to colleagues, or find themselves drawn into the drama. These may all may feel better in the short run than dealing directly, clearly and specifically with root causes.

But, in professional settings, bruised feelings tend to build over time, simmering rather than boiling over, until they build to a flash point where the pyrotechnics can be fatal.

I learned this early in my career when I made the mistake of ignoring what appeared to be little more than a slowly-building exasperation. Eventually, my high-potential direct report threatened a young team member not merely with his job, but with ever working again.

As reports of the threat spread, a mutiny developed until the manager's exasperation turned menacing, and he--not his threatened young charge--was engulfed in his own job-ending crisis. It would have been much better for everyone had I diffused the ticking time bomb when I first saw it, rather than allowing it to explode under pressure.

Here are five techniques I've learned from taking on the hard, but important, job of diffusing emotionally-charged interpersonal conflict:

1. Set the scene.

You won't be able to control everything, but you can control the setup. Atmospherics matter.

Choose a time when your colleague is not stressed, and a place and time where you can talk without being rushed or interruptions. Walking meetings outside can be a good idea--fresh air and movement can help burn off nervous or angry energy.

Wherever you meet, allow your colleague appropriate privacy. Unless this is an HR-level issue, leave the audience and referees out of it.

2. Set the table.

Make clear right away what you want to discuss: "I've been wanting to talk with you for a while about something that's getting in the way of our working well together. I'd like to discuss how we might fix what's causing it."

Easing into it, or asking how they are feeling, or otherwise dancing around your intention will only create an awkward tension. You want to be assertive, not aggressive.

Once you have stated your intention, offer that you'd like to hear their perspective first. It's a sign of goodwill and respect.

3. Listen like it's your job.

Next, you need to actively listen. This is not the time to make your case, no matter how much you want to defend yourself.

Do not react. Don't interrupt, except for clarification. Repeat back what they have said, expressing that you want to be sure you understand.

This does not mean you agree. In fact you may find yourself ready to explode listening to their story. You may be listening to what sounds very much, to your ear, slander and lies. Stay calm. Remind yourself that you are not your emotions.

Your job here isn't done until you have fully heard, and can reflect back to your colleague that you truly do understand, their point of view. Many tough discussions can be disarmed through good listening.

4. Don't cross the wires.

Remember, you are diffusing a bomb. It requires calm and care. Someone may say: "You are such an idiot!" (or, let's be real, perhaps much worse), or "I'll see you in court!"

You need to stay cool. If you cross the wrong wires, you will blow everything up. Remember that you're not accepting abuse; you're being the bigger person.

Success in high stress conversations demands that you de-escalate. It's a kind of Judo, where a principle is "softness controls hardness." In fact, if your colleague yells or gets angry, it's time to lower your voice.

5. Respond with concern.

You may now need to make clear that you don't see some things the same way. Frame the discussion as an interest of growth and forward movement: "I understand your point of view, and while I don't necessarily agree with all of it, I very much want us to work well together."

Present a simple and fair plan, discuss it in a spirit of compromise and mutual respect. In the end, you might need to agree to disagree on some fundamental issues, but you can still ask for some trust to move forward with a plan.

From here, exit stage left; no need for an extended conclusion. It's important for the conversation to percolate in the mind of your colleague. If you've managed to be fair and listen well, there's a good chance you've diffused the bomb, and you will have set yourself up for better success with this colleague in the future.