Cold shock lasts about a minute, and floating through it works
What happens
Sudden cold triggers a gasp and rapid breathing you cannot control. Trying to swim during it is how water is inhaled.
What to do
Lie back, spread your arms and legs, and let your head go back. Keep still for sixty to ninety seconds until breathing settles.
Then
Once you are breathing normally, decide whether to swim or call for help. Both are possible; neither is in the first minute.
