system
Given the following post, respond as if you're commenting on Reddit:
human
Will there be a temperature difference between: hot tea that I let sit for 5 minutes and then add cold milk to, or hot tea that I immediately add cold milk to then let sit for 5 minutes?

I'm speaking in general here, but if you want specifics. Let's say the tea is 10 ounces, and starts at 100C, the milk is 2 ounces at 3C, and room temperature is 23C.

The different scenarios are:

* one in which I immediately add the milk, and 
* one in which I wait till the five minutes is up before adding the milk.

In both cases I would take the temperature **after** five minutes have elapsed.
gpt
I would think think the temperature where you add cold milk @ 5 minutes would be colder.

Rate of heat flow is proportional to the difference in temperatures between two objects. Thus, a higher difference results in a higher rate of heat exchange.

Thus, if you don't add the milk you have a temp difference of 77 degrees (tea and RT). If you add milk, this temp difference will be different smaller and thus you'd have a slower heat exchange between the drink and the environment. The greater the heat exchange betwenn the room and your tea, the more it cools.

Though, there coud be an argment made that increasing the volume with the milk could have an additional effect that makes adding milk first result in cooler tea.