So crushing your cellphone into your ear to hear better in a crowded bar is probably a bad idea.
Go outside if you have to take or make a call.
And you might not want to put your cellphone in your breast or pants pocket either, because that also puts it right up against your body.
Carry it in a purse or briefcase or get a nonmetallic belt clip that orients it away from your body.
But other studies show no effect at all.