GPS Tracking your child

I have always wondered how we could use GPS receiver embedded into the clothing of our Autistic son, so that should he stray, we could track him down. We clutch him tightly in crowded places and don't lift our eyes from him. We have also wanted to put some id or contact details on him so that some person finding him can direct our non verbal autistic son back to us .. Just in case >>

The Good news. I read someone has come up with a suitable device. The Bad news, its available currently on in the US and Canada; and even by their standards, its fairly expensive.

The device is called Amber Alert GPS , requires an initial payment for the device, and then a monthly subscription. Still a very handy device. Small and could be put into a convenient place of clothing or a carry on bag etc.
Details are available on their website.
https://www.amberalertgps.com/