Worry far more about the sun: "Hence, a cell phone cannot transmit more than 0.125 Watts of energy to your head, while sunlight will transmit 43.8 W. This means that sunlight heats your head 350 times faster than a cell phone. In fact, since sunlight is a much higher frequency than cell phones, the sunlight energy is more dangerous (see Equation [1])."

1. https://www.antenna-theory.com/tutorial/cancer/cellphone.php....