For pouring hot things into a mug, you can buy a nifty gadget that goes over the rim of the mug and makes a sound when the water hits the probes.

$1 is one of several varieties you can easily find.

I'm having a hard time imagining what you mean by the set of three baking items in order to help - how do these fit together and what does it do?

This is not required this sounds bad but it isn’t.

Poor slowly and eventually you’ll get how long you need to do this for. But pour slowly then stop once in a while. I recommend washing hands thoroughly. Then quickly reach in to the glass and touch where it is. Once you have attained the info withdraw your hand if it’s brief it won’t burn you. Pour slowly and carefully you can sometimes track by the outside of the glass but touching the liquid will help. But quickly and briefly. It’s safe. I do this all the time.