I just realized there was a “sweets” subforum, so I’m going to stick an unanswered question here!
And an answer I found
“When you work with tempered chocolate, it is crucial to keep it at the proper temperature. If it cools too much, it will thicken and set. If it is too warm, it will no longer be tempered and will not set properly. Dark chocolate should be used at 86° to 90°F, milk chocolate at 84° to 87°F.
“There are several options for maintaining this crucial temperature:”