The person working late should still hear ordinary affection before the conversation ends.

When someone is buried, the exchanges around them turn into logistics: what time, who is collecting whom, whether there is food. Warmth gets postponed until the busy stretch ends, and busy stretches have a way of running into each other. The person working late is often the one most in need of a sentence that has nothing to do with the work, because everything else reaching them is a demand.

Before you end the next call or message with someone in the thick of it, add one ordinary line of affection. It does not need to be large or well timed.