Answer:
Hard to catch, easy to hold. Can't be seen, unless it's cold
A mile from end to end, yet as close to as a friend. A precious commodity, freely given. Seen on the dead and on the living. Found on the rich, poor, short and tall, but shared among children most of all.
Turn us on our backs and open up our stomachs you will be the wisest of men though at start a lummox.
Without this, eating food and Steven Spielberg's career would be very different.
It can cause deflation of tires when dropped from the rear of spy cars.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?