Of course you will get cance if you won't use uv filters. Cancer is caused by ionizating radiation, so everything under 320-380nm it's UV light - X-rays - Alpha, Beta and Gamma rays, because the are destroying DNA chain (they have enought quantum power to knock out electrons from the atom). So yes, you can get cancer from the sunlight, because it's contain some amount of UV light.
But everything above 380nm is safe. It's: visible light - infrared - radio waves. They are safe because they don't have anought quantum power to influence in DNA chain (And degradation of DNA chains is source of cancer). But what about heating by radio waves? So, Microwaves works by causing water molecules to vibrate. And yeah it can heat up human body... BUT. Just look how much power have microwave owen (average ~800W) and hov long takes it to warm up a cup of water. Now, compare this power to power of any radiowave source you are using, Wi-Fi router have max 1W of power, and phone have probably max 500mW, but I think it's even less. So, is this can heat up human body? No, because human body have excellent cooling system.