Drowning

Question 1

Diving reflex

Answer 1

Parasympathetic response, greatest at less than 6 months and decreases with age
Includes bradycardia, apnea, peripheral vasoconstriction.
Used to be think it provided transient protection for drowning but no longer though to be the case

Question 2

Cold water submersions

Answer 2

Cerebral protection from rapid central nervous system cooling rather than dive reflex

Question 3

Some things to remember for drowning

Answer 3

Unless they're awake and talking, prognosis is unknown. 
Consider trauma (although rare at 0.5%), syncope, arrythmias etc as underlying cause