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Immersion and drowning
Published in Jason Payne-James, Richard Jones, Simpson's Forensic Medicine, 2019
Jason Payne-James, Richard Jones
The cold shock response, which is initiated by peripheral subcutaneous receptors, causes respiratory effects (inspiratory gasp and uncontrolled hyperventilation, respiratory alkalosis and cerebral hypoxia) and cardiovascular effects (tachycardia, increased cardiac output, hypertension and ‘heart strain’ potentially leading to cardiac irritability and ventricular fibrillation), which appear temperature dependent.
Cold water immersion
Published in Mike Tipton, Adam Wooler, The Science of Beach Lifeguarding, 2018
The cold shock response comprises a range of cardiorespiratory responses (Figure 6.1) initiated by the stimulation of skin cold receptors on rapid cooling of skin temperature [7–11]. The superficial subepidermal location of these receptors (about 0.18 mm below the surface of the skin) explains the rapidity of the cold shock response and why subcutaneous fat does not protect against it. Within limits, the magnitude of the cold shock response is related to the rate of change of skin temperature (temporal summation) and the surface area of the body exposed (spatial summation) [12]. In naked individuals, the response peaks in water between 10°C and 15°C [13].
Applied exercise physiology and the environment
Published in Nick Draper, Helen Marshall, Exercise Physiology, 2014
The initial response begins immediately on contact with water and peaks at around 30 seconds. Symptoms begin to subside as the immersion duration approaches three minutes. The initial or cold shock response does not occur on entry to warm water and is thought to be a response initiated by cold receptor stimulation. Research indicates that a greater response occurs the colder the water and for those who have had fewer cold water immersions. The cold shock response is thought to be the primary cause of death in incidents when individuals drown within three metres of safety. The cold receptors primarily trigger CNS-driven alterations in breathing and circulation. On entry to cold water (below 15°C) there is an immediate increase in the respiratory drive. This results in an individual taking an initial large gasp of air (around 2–3 litres) followed by the initiation of hyperventilation, where the rate of breathing is increased without an increase in depth of breathing. The incidence of hyperventilation can cause dizziness and confusion and is consequently thought to add to the panic associated with the immersion. Golden and colleagues believe that the most significant risk involved in the cold shock response relates to a decrease in breath-hold time – reduced from around 60 s on land to around 10 s in the water. The decrease in breath-hold time results in an increased risk of water inhalation and drowning.
Human cold habituation: Physiology, timeline, and modifiers
Published in Temperature, 2022
Beau R. Yurkevicius, Billie K. Alba, Afton D. Seeley, John W. Castellani
Acute cold exposure also causes changes in other physiological systems, including the cardiovascular system. The common response that occurs over different types of cold exposure (whole-body air and water, hand immersion) is an increase in mean arterial pressure (MAP), which is primarily mediated by an increase in total peripheral resistance [53,54]. Furthermore, prior and concurrent to vasoconstrictor and metabolic thermoeffector responses, an immediate cardiorespiratory response occurs during accidental cold water immersion and is known as the cold shock response (CSR). The CSR is characterized by a large gasp for air followed by an acute increase in cardiovascular (HR, MAP) and respiratory (tidal volume, breathing frequency) responses [55,56]. As cold water exposure continues, vasoconstrictor and shivering responses are increasingly engaged to defend body core temperature.
Residual effects of short-term whole-body cold-water immersion on the cytokine profile, white blood cell count, and blood markers of stress
Published in International Journal of Hyperthermia, 2021
Milda Eimonte, Henrikas Paulauskas, Laura Daniuseviciute, Nerijus Eimantas, Astra Vitkauskiene, Gintare Dauksaite, Rima Solianik, Marius Brazaitis
Accidental falls into cold/icy water are relatively common in some recreational and occupational activities. The worldwide popularity of wintertime recreational activities, open cold-water swimming, and cold/icy water immersion immediately after acute exercise has led to an increase in the total number of people exposed to extreme cold environments [1–5]. In non-cold-adapted people, initial head-out cold-water immersion (CWI) at a water temperature below 15 °C is a physiologically stressful event that induces a response known as the “cold shock” response, which can be particularly hazardous [2,6,7]. This response occurs exclusively via stimulation of low-temperature-sensitive receptors (e.g. TRPM8 and/or TRPA1) in cutaneous nerve endings [8–10], which evokes inspiratory gasps, hyperventilation, tachycardia, peripheral vasoconstriction, and increased blood pressure.