The phrase "precious seconds" means that every second is valuable and important. It implies that time should be cherished because it is limited and cannot be regained. Full definition
You can waste precious seconds of workout time measuring the distance to get it right. (onnit.com)
You'll know you have coverage for your personal property, and you can spend those few precious seconds escaping instead of trying to gather the most important things. (effectivecoverage.com)
Most people were either at work or at least awake for the day, which saved precious seconds for all the residents as they tried to escape. (effectivecoverage.com)