Do you have a big frosty box of Eppendorf tubes where you can’t read the tops? Rubbing of the frost not working?
I found that quickly blowing the tops with a heat gun does the trick, while barely warming up the samples.
You can always get a cheap-o heat gun like this one from Home Depot rather than paying hundreds for a “science” heat gun from a scientific supplier, but it probably will die on you sooner. A hairdryer can work in a pinch.
Happy defrosting and label-reading!