How to insert icon or image on PHPMailer Subject field

I’m trying to insert a siren icon on my Subject field but I’ve no idea how to do it since the field doesn’t accept special characters nor images.

I’m using PHPMailer and my goal is to get on something like this: Print of a Email subject in my mailbox

Answer

This is just an emoji. To be clear, this one: 🚨

In order for you to use emojis in your subject or email body, you need to set the charset to UTF-8

$mail = new PHPMailer();
$mail->CharSet = 'UTF-8';