[Chris]

Chris asked the Naked Scientists:

Does drinking hot drinks like tea kill off bacteria in the mouth?

What do you think?

[blakestyger]

Probably not - there are bacteria called thermophils that can withstand much higher temperatures than you would be able to bear in your mouth, something like 70C+. These may not necessarily be thermophils but I guess that in the order of things a mouthful of tea isn't that hot in microbial terms.

[TonyCap]

It's not the heat, but tea does kill bacteria in the mouth.  I've read recommendations to drink black tea to get rid of bad breath.