There was a picture in this question about space debris on shore. Seems to be a part of a Falcon 9.
The round stickers are used for temperature control. Similar labels are sold by some companies, for instance Spirig. The labels do permanently record exceeded temperature levels by permanently blackening the corresponding former white indicating levels. But the time and duration of eceeding the level is not recorded.
But what temperatures should be recorded, during launch preparation, atmospheric flight or reentry? Apparently the temperature was higher than the record interval of 40, 43, 46, .. 104 and 110 °C as all dots are black.