Summer is around the corner and locals and visitors alike are ready to get out and enjoy Lake Tahoe. Before taking a plunge, there are important precautions to keep in mind with water surface temperatures and cold water immersion.
Lake Tahoe’s temperatures are on the colder side at the beginning of the summer, ranging between 50 – 60 degrees Fahrenheit. Although these temperatures will continue to rise to 65 – 75 degrees as the days get hotter and the summer carries on, keep in mind that symptoms of cold water immersion can occur at water temperatures as warm as 77 degrees. There are four stages to cold water immersion:
Stage 1: Initial Cold Shock
Sudden immersion into cold water can cause immediate, involuntary gasping for air, panic, and vertigo as well as create changes in your body's blood pressure and heart rate. The sensation of taking your breath away can result in panic and inhalation of water and drowning. If you do fall in or enter the cold water, attempt to get control of breathing and try not to panic. Focus on floating with your head above water, until the initial cold shock phase passes. If it doesn’t pass, it’s time to get out of the water.
Stage 2: Short-Term Swim Failure
Swim failure occurs anywhere from 3-30 minutes following the initial cold water shock. In this phase, the muscles and nerves in the legs and arms will begin to cool quickly, causing strength and movement to drop significantly. Even if they’re in good physical condition, this stage of cold water immersion can render a person unable to pull themselves out of the water or keep their head above the water. It’s recommended to not swim alone in Lake Tahoe, and if you or someone you’re with experiences short-term swim failure, place your body in a floating position if possible and get to shore or aboard a watercraft quickly to begin the rewarming measures.
Stage 3: Long-Term Immersion Hypothermia
Hypothermia sets in after 30 minutes of cold water exposure, depending on the water temperature; as cold water causes the body to lose heat 25 times faster than cold air. Hypothermia is a cooling of the body’s core temperature caused by active heat loss and the failure of the body to produce more heat. Recognize signs of hypothermia to help identify its early onset: shivering slurred speech; cold and bluish lips, skin and fingernails; loss of feeling in extremities; confusion; dizziness and rigidity in extremities. If hypothermia is suspected, take action by starting rewarming measures and seek medical attention by calling 9-1-1 or going to the closest medical facility.
Stage 4: Post Immersion Collapse
It’s important to note that post immersion collapse can occur at any point. Your body is still in danger while being rescued from cold water or after. Cardiac arrest after cold water immersion occurs due to the collapse of the arterial blood pressure. Along with hypothermia, possible water in the lungs due to inhalation, or coagulation issues due to cold and thickened blood.
To have a fun, safe time on the water, practice simple “dos” and “don’ts” such as making sure to wear a personal flotation device at all times. If you’re operating a boat, ensure there are life jackets for every passenger aboard. Avoid jumping off large rocks into deep water, as this runs the risk of increased cold water immersion and trauma, based on the height of your jump.
If you or someone you’re with is experiencing symptoms of cold water immersion or hypothermia and rewarming measures can’t be met as soon as possible, it is vital to seek medical attention or call 9-1-1. Barton Health’s emergency department is safe, accessible, and available around the clock for Lake Tahoe’s residents and visitors alike.
Recognizing the four stages of cold water immersion and signs of hypothermia prevents emergencies, injuries and helps to keep you and your family safe around the lake this summer.
Barton Memorial Hospital’s Level III Trauma Center provides medical services for trauma care and the immediate availability of emergency medicine physicians, surgeons, nurses, lab and x-ray technicians, and life support equipment 24-hours a day.
