Safety
What sea temperature is safe to swim in?
How cold is too cold, what cold shock is, and the practical rules for beach swimmers.
5 min read
There is no single safe number. Trained cold-water swimmers happily swim at 5°C; an unacclimatised summer bather can be in real trouble at 14°C. What matters is your conditioning, how long you stay in, and whether you have a safe exit.
Practical guidelines
- Above 22°C: comfortable for almost everyone, no time limits for healthy adults.
- 18–22°C: refreshing; most swimmers acclimatise in 1–2 minutes.
- 14–18°C: cool water — short swims unless trained.
- Below 14°C: cold-water territory — enter slowly, wear neoprene, limit to a few minutes if untrained.
- Below 10°C: real risk of cold shock — train, never swim alone.
Cold shock vs hypothermia
Cold shock is the first minute — gasp reflex, hyperventilation, racing heart. Most cold-water drownings happen in this window. Hypothermia takes longer (10–30 minutes in cold water). The fixes are different: cold shock needs slow entry and breath control; hypothermia needs you out of the water and rewarmed.