I take from the discussion that most of this community has never seen a well-designed frying pan.
The handle is not supposed to get hot. It doesn't need silicon or whatever outside of it, just well designed metal is enough. Cast iron is perfectly fine, people do it with aluminum all the time, and cast iron is an order of magnitude (literally, a bit more than 10x) easier to keep cool.
You don't need 23th century engineering to make it. In fact, people have been making it since the 19th century.
I've never seen a cast iron pan that the handle stayed cool. With aluminum the handle can be a thin hollow piece riveted on so very little heat is conducted to the handle and it stays cool (assuming you're not cooking with gas). Cast iron is a big thick handle built right into the pan (because they're heavy) an and tends to be shorter (because cast iron is brittle) so it'll get hot as the heat conducts no problem. That's why many cast iron pans come with a potholder for the handle (even the expensive ones) and other types of pans don't.
Mine stay cool enough to handle on the stove top, except if simmering something for some time (which I don't usually do with cast, because that often entails tomatoes).
I can make steaks or burgers in cast and pick it right up, whole cooking.
How do the handle connects with the pan at the frying pans you know? Through a solid slip like if the part of it you hold was just inserted into the main body metal?
Cast irons are ...casted iron. They are a single piece of metal, which includes the handles. If anything,the average cast iron pan is thicker where the handle meets the pan due to cast iron being brittle and heavy.
This being an example of the most popular line of cast irons, due to its quality:cost ratio.
I've found a photo on Google of one with a much more reasonable handle. Notice it's not plane, and it connects to the pan making a W, with walls thinner than the pan's. You can get even better by making the connection with a long U shape.
Cast iron's heat transfer is quite poor. It's about 1/5 of aluminum and 1/10 of copper. You can test this yourself if you have a laser thermometer. Heat the pan for a bit and then scan the pans surface with the thermometer. You'll see a fair amount of variation.
I think people understand this property and rotate the pan to get an even hest distribution. Any case ... Could be wrong, but I looked up the heat transfer coefficient and its a fraction of copper and aluminum. On the other hand, it's really good at staying hot once it gets hot.