The most important thing you can ever do in a potentially life threatening situation is breathe (when possible) and focus on doing things, calmly.
If nothing else works, put your finger down your throat, kids.
You never want to go to a second location.
… unless absolutely necessary i.e. a child etc. Drowning people tend to clasp on their rescuers and drag them under with them. Find something to throw or a some sort of lifeline.
As much as you’d feel more comforted if the lights were on, you know your house better than anyone.
… you are probably having a heart attack.
… where you’re going and when you should be back. If you become incapacitated, this will increase survival chances by a lot.
People searching for you will start at your last known location/heading.
… do NOT pull it out. Doing so can make you bleed out.
leave immediately. If it’s not safe enough for the kids, it ain’t safe for you.
… stuffed with pillows/blankets before they lay down. That way they can’t roll over and asphyxiate themselves.
You don’t need to be Michael Phelps, but it’s great to be able to swim decently and tread water.