Managing Medical Conditions: Hypothermia, Heat Exhaustion & Dehydration
Environmental and Fluid-Related Conditions in Sport
Alongside the conditions covered in earlier lessons, sports performers are also at risk from conditions caused by the external environment and inadequate hydration. Hypothermia, heat exhaustion and dehydration are all examinable in this unit. Each is directly linked to the extrinsic factors studied earlier, particularly weather and temperature conditions.
Hypothermia: Causes and Symptoms
Hypothermia occurs when the body's core temperature drops below 35 degrees Celsius. In sport, the two key causes are: the body losing heat faster than it can produce it in cold conditions (body temperature drops below 35°C) and prolonged exposure to cold or wet conditions — for example, a cross-country runner in rain and wind, an open-water swimmer or a cyclist descending a mountain. Inadequate clothing significantly increases this risk.
The five symptoms of hypothermia listed in the specification are: shivering (the body's automatic attempt to generate heat through muscle activity), blue lips or skin (cyanosis — reduced blood flow to the periphery as the body prioritises core organs), slurred speech (cold affects neuromuscular coordination), tiredness or confusion (the brain functions less effectively as core temperature falls) and slow breathing (respiratory rate drops as metabolism slows in the cold).
Hypothermia: Treatment
Treatment for hypothermia involves gently warming the performer. The two specification treatments are: remove wet clothing and wrap in blankets, covering the head (wet clothing conducts heat away from the body rapidly, so removal and insulation are the first priority — covering the head is important because significant heat loss occurs through the scalp) and give a warm, sugary, non-alcoholic drink (warm fluids raise core temperature from the inside; sugar provides a rapid energy source; alcohol must be avoided as it causes blood vessels near the skin to dilate, actually increasing heat loss).
Hypothermia must NOT be treated with a hot bath, hot water bottle, or by rubbing the body parts — these cause rapid vasodilation that can send cold blood from the periphery to the core, causing cardiac complications. Warming must be gradual and gentle.
Heat Exhaustion: Causes and Symptoms
Heat exhaustion occurs when the body overheats, typically with a temperature of 38 degrees Celsius or above. Three causes are listed: body temperature reaching 38°C or above (the body's thermoregulatory mechanisms begin to fail), strenuous physical activity (generating high levels of internal heat that the body cannot dissipate fast enough) and not enough water intake (without adequate fluid, sweating — the primary cooling mechanism — is impaired). Hot, humid environments make heat exhaustion more likely because high humidity prevents sweat from evaporating effectively.
The five symptoms of heat exhaustion are: excessive sweating (the body's cooling attempt, which causes significant fluid loss), headache or dizziness (dehydration and reduced blood pressure to the brain), being very thirsty (the body signals its fluid deficit), feeling or being sick (nausea and vomiting caused by dehydration and heat stress on the gastrointestinal system) and rapid pulse and/or rapid breathing (the cardiovascular system working harder to circulate blood and transfer heat to the skin).
Heat Exhaustion: Treatment
Treatment for heat exhaustion is straightforward and must be applied quickly before the condition deteriorates into heatstroke (a life-threatening emergency). The two specification treatments are: move the performer to a cool place and cool their skin — for example, move them into the shade or an air-conditioned area, loosen clothing, apply cool damp cloths to the skin or use a fan — and get them to drink plenty of water to replace the fluid lost through sweating. If the performer does not improve within 30 minutes or becomes confused or loses consciousness, call 999.
Hypothermia: core body temperature below 35°C. Heat exhaustion: body temperature of 38°C or above. These are the threshold temperatures specified by the specification and must be learned precisely.
Dehydration: Causes, Symptoms and Treatment
Dehydration is caused by loss of bodily fluids — primarily through sweating during exercise — that are not adequately replaced. In sport, dehydration impairs thermoregulation, reduces blood volume, slows reaction times and decreases strength and aerobic capacity. There is a direct link between dehydration and both diabetes — because high blood sugar causes the kidneys to excrete more water — and heat exhaustion, since dehydration prevents effective sweating.
The four symptoms of dehydration are: feeling thirsty (thirst is actually a late sign — by the time you feel thirsty, performance is already impaired), fatigue (reduced blood volume means less oxygen delivered to muscles), dark yellow urine and infrequent urination (the kidneys conserve water by concentrating urine — pale urine indicates good hydration; dark urine indicates dehydration) and dry mouth or lips (reduced saliva production as the body conserves fluid). Treatment is simple: drink plenty of water as the first step, with rehydration sachets (oral rehydration salts) used in cases of significant fluid and electrolyte loss to restore the correct balance of water and minerals.
The best approach to dehydration in sport is prevention. Performers should hydrate well before training, drink regularly during activity (approximately 150–250 ml every 15–20 minutes in moderate conditions, more in heat), and continue rehydrating after training. Coaches should build regular drink breaks into sessions and ensure water is always available at training venues. Monitoring urine colour is a practical and reliable way for performers to self-assess hydration status. Diabetic performers must be especially vigilant as high blood sugar can cause increased urination (polyuria), accelerating dehydration.
The specification explicitly links weather and temperature conditions to medical risk. Cold, wet weather increases hypothermia risk — appropriate clothing and a warm-up that raises core temperature both mitigate this. Hot, humid conditions increase heat exhaustion and dehydration risk — session scheduling, shade, cooling zones and mandatory hydration breaks are control measures identified in a risk assessment. Coaches should always check weather forecasts before outdoor sessions and have a written protocol for extreme conditions as part of their Emergency Action Plan.