LetHotPagesCool is a Wiki editing guideline.
Context
WikiWikiWeb pages can grow very quickly. That can be a good thing (e.g. BrainStorming). However, ThreadMode argument often generates MoreHeatThanLight. Such pages can degenerate into noise.
Therefore, let hot pages cool before contributing.
Wait a little while. Write your contribution in a text editor and hold onto it for ten minutes, an hour, a day or maybe a month. Wiki lives in the LongNow. After that, come back to the page, reread it, and decide whether your contribution (a) still merits adding, (b) hasn't been said by someone else, and (c) follows GoodStyle. If it satisfies these criteria, post away.
Later, WhenFlowersFinishTrimStem.
Dealing with Insults
LetHotPagesCool, or something similar, is also recognized at other sites like WikiPedia. The link at http://en.wikipedia.org/wiki/Wikipedia:Staying_cool_when_the_editing_gets_hot has good advice for people who perceive they have been targeted for unwarranted insults.
There is "hot" in a conversation that's progressing rapidly, and there is "hot" in a heated argument. I think the two are different, and that LetHotPagesCool applies to the former while CoolingOffPeriod is more suitable for the latter - it's not the page that needs to cool, but the authors. Asking people who need a CoolingOffPeriod to LetHotPagesCool is unlikely to make much difference. Mix or split the concepts?
I've found that this has merit when contributing to cool pages, too. The time between writing and posting reveals the gap between what I want to say and what I almost said.
Letting hot pages cool also gives others a chance to contribute.
Most wikis have a "minor changes" button that keeps discussion threads off RecentChanges, where they might pick up additional combatants. For this purpose, Japanese-stype anonymous BBSes like 2ch allow you to reply to a thread without bumping it to the top by typing "sage" in the email field.