The International Ice Swimming Association – www.internationaliceswimming.com
The International Winter Swimming Association – https://iwsa.world/
BLDSA – http://bldsa.org.uk/
Great Swim – http://www.greatrun.org/great-swim
Chill Swim – http://www.chillswim.com
Cold Water Shock, Core body temperature and hypothermia – http://beyondcoldwaterbootcamp.com/4-phases-of-cold-water-immersion
Water Quality – http://www.wildswimming.co.uk/quick-guide-water-quality/
Current and Rip-Tides – http://www.wikihow.com/Stay-Safe-Around-Rip-Currents
Under water hazards and lack of visibility – http://www.river-swimming.co.uk/safety2.htm
NHS Advice: http://www.nhs.uk/Livewell/bites-and-stings/Pages/Safe-swimming.aspx