Yeah their comment doesn’t seem right to me. After a bit of googling I found this answer talking about heating things up to see relativistic effects, however because the velocities of the atoms in an object that has been heated up are random it’s most likely not possible to detect any relativistic effects. https://physics.stackexchange.com/questions/351773/is-there-a-relation-between-fluctuations-temperature-and-time-dilation