What is the reason for your worries? It is certainly not anywhere near the frequency/energy range of ionizing radiation, which begins beyond the far ultraviolet wavelength of around 100 nanometers. We are still talking about microwaves here, not even close to the visible light spectrum. You might observe RF heating (like with a microwave oven) if you stand near a source putting out enough energy.
And in terms of wireless engineering, if the phone heats your brain, it wastes a lot of energy that should go into communication instead.
Maybe that's an idea for an extra, so let's backlog it. But yes, please focus on connection quality and not melting heads.
There’s a lot of articles/papers out there citing potential risk. Here’s one page summarizing (note I don’t know who is funding this page, but the skepticism seems merited): https://mdsafetech.org/5g-telecommunications-science
I think the questions remain around non-stop skin absorption once we blanket the population with it.
Only in the sense that the jury is still out on wifi and 4G - which is sorta true, but most people aren't that concerned about it.
But those pass thru the body whereas MMW gets absorbed. Plus just because most people aren’t concerned (it doesn’t seem to be catastrophic given number of years deployed) doesn’t mean there aren’t potential long term consequences (note most people weren’t concerned with leaded gasoline either...)