Choque de água fria e hipotermia: o que fazer

Última verificação: 14 de outubro de 2026

Passo a passo

1. Primeiro flutue, não nade

   A água fria faz arquejar e respirar muito depressa. Resista à vontade de nadar ou de se debater. Incline a cabeça para trás com as orelhas dentro de água, abra os braços e as pernas e flutue até a respiração acalmar.[1][2][3][5]

2. Mantenha a boca e o nariz fora de água

   O colete salva-vidas mantém a boca e o nariz fora de água enquanto controla a respiração. Se não tiver colete, agarre-se a qualquer coisa que flutue.[6][4]

3. Peça ajuda assim que conseguir respirar

   Quando a respiração estiver controlada, grite, apite ou use o rádio, o telemóvel ou a baliza para pedir ajuda.[3]

4. Use os 10 minutos seguintes para sair

   Os braços, as pernas e os dedos vão enfraquecer ao longo dos cerca de dez minutos seguintes. Use esse tempo para voltar a bordo ou subir para qualquer coisa que flutue, e tire da água a maior parte possível do corpo.[7][12]

5. Só nade se a segurança estiver perto

   Nadar faz perder calor mais depressa. Só nade para chegar a outras pessoas, a um barco ou a terra que tenha a certeza de alcançar. Não nade para se aquecer.[8][14]

6. Sozinho e sem conseguir sair: posição HELP

   Fique quieto para poupar calor. Cruze os braços com força sobre o peito e puxe os joelhos para cima, na direção dele, com a cabeça fora de água.[9][11][14]

7. Com outras pessoas: juntem-se

   Juntem-se com os peitos encostados, os braços à volta das costas uns dos outros e as pernas juntas. Isto abranda a perda de calor e mantém o grupo unido para as equipas de salvamento.[10][22]

8. Depois do resgate: levante com cuidado e deite a vítima

   Se possível, tire da água uma vítima de frio deitada em vez de na vertical. Manuseie-a com cuidado e leve-a o mais depressa possível para um local quente, seco e abrigado; a temperatura interna pode continuar a descer depois do resgate.[15][13]

9. Aqueça-a devagar

   Retire a roupa molhada e embrulhe-a num cobertor, num saco-cama ou numa toalha seca, cobrindo a cabeça. Se estiver totalmente acordada, dê-lhe uma bebida quente sem álcool e algo doce para comer.[17][19]

10. Procure assistência médica

    A hipotermia é uma emergência médica que exige tratamento hospitalar. Ligue para o número de socorro ou de emergência local.[20]

O que não fazer

• Não tente nadar com força no primeiro minuto. Deixe primeiro passar o choque do frio.[1]
• Não nade só para se aquecer. Acelera a perda de calor.[8][14]
• Não ponha uma pessoa com hipotermia num banho quente nem lhe esfregue os braços, as pernas, as mãos ou os pés.[18][21]
• Não dê álcool a quem está com frio.[23]
• Não tire uma vítima de frio da água na vertical se a puder tirar deitada.[15]

Antes de largar

• Antes de largar: use um colete salva-vidas ou um auxiliar de flutuação. Aumenta muito as suas hipóteses de ultrapassar o choque inicial.[6][24]
• Antes de largar: vista-se de acordo com a temperatura da água, não a do ar.[25]
• Antes de largar: considere água fria toda a água abaixo de 15 °C. Em muitos sítios, isso abrange grande parte do ano.[26]
• Antes de largar: leve consigo um meio de pedir ajuda, como um rádio VHF, uma PLB ou uma EPIRB.[27]
• Antes de largar: pratique flutuar num local vigiado, como uma piscina.[28]

Perguntas frequentes

Fontes

As fontes são citadas na língua original.

1. RNLI (2026-10-14): “Take a minute. The initial effects of cold water pass in less than a minute so don’t try to swim straight away.”
2. RNLI (Float to Live) (2026-10-14): “The best way to float is to tilt your head back with your ears submerged.”
3. RNLI (Float to Live) (2026-10-14): “Try to relax and breathe normally. You can gently move your hands and legs to help you stay afloat if you need to. Spread your arms and legs out to improve stability – and it's OK if your legs sink, we all float differently. Once your breathing is under control, call for help or swim to safety.”
4. US National Weather Service (NOAA) (2026-10-14): “If possible, utilize any floating objects to get out of the water.”
5. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “During cold shock, a person will take a sudden, deep gasp of air, then start to hyperventilate. This can be 600-1000% faster than normal breathing and it’s the body’s automatic response. This lasts about one minute.”
6. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “Wearing your lifejacket during this stage will keep you afloat, with your mouth and nose out of the water, so you can focus on your breathing.”
7. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “For the next 10 minutes or so, you will lose meaningful movement in your arms, legs and fingers. Focus on self-rescue. If that isn’t possible, find a way to keep your airway out of the water and wait for rescue.”
8. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “Only swim if you can join others or reach safety. Don’t swim to keep warm.”
9. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “Cross your arms tightly against your chest and draw your knees up close to them to help you keep your body heat.”
10. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “Huddle with others with your chests close together, arms around your mid to lower backs, and legs woven together. This also helps keep your group together until help arrives.”
11. US National Weather Service (NOAA) (2026-10-14): “If you cannot get to safety, assume the Heat Escape Lessening Position (H.E.L.P.) position. This protects the critical body areas and slows down the loss of heat.”
12. US National Weather Service (NOAA) (2026-10-14): “Keep as much of your body out of the water as possible.”
13. US National Weather Service (NOAA) (2026-10-14): “After escaping from cold water, get into a warm, dry, protected environment as quickly as possible. Even removed from cold water, a victim’s core temperature can continue to drop to dangerous levels.”
14. IMO – Guide for Cold Water Survival (MSC.1/Circ.1185/Rev.1) (2026-10-14): “Do not attempt to swim unless it is to reach a fellow survivor or a nearby shore, craft, or other floating object onto which you can hold or climb. Staying calm and still conserves heat.”
15. IMO – Guide for Cold Water Survival (MSC.1/Circ.1185/Rev.1) (2026-10-14): “Ideally, the survivor should be recovered in a horizontal or near-horizontal body position. Lifting a hypothermic person vertically can induce cardiac arrest.”
16. IMO – Guide for Cold Water Survival (MSC.1/Circ.1185/Rev.1) (2026-10-14): “It is important to remember that they will last only about three minutes and will then ease.”
17. NHS (2026-10-14): “remove any wet clothing, wrap them in a blanket, sleeping bag or dry towel, making sure their head is covered”
18. NHS (2026-10-14): “do not use a hot bath, hot water bottle or heat lamp to warm them up”
19. NHS (2026-10-14): “give them a warm non-alcoholic drink and some sugary food like chocolate if they're fully awake”
20. NHS (2026-10-14): “Hypothermia is a dangerous drop in body temperature below 35C (normal body temperature is around 37C). It's a medical emergency that needs to be treated in hospital.”
21. NHS (2026-10-14): “do not rub their arms, legs, feet or hands”
22. NSW Government (Transport for NSW) (2026-10-14): “If you're in the water with others, huddling is the best method of reducing the risk of hypothermia. Huddle close together to protect your chests and arms. This can reduce the rate at which your bodies lose heat and can increase survival time by up to 50%.”
23. NHS (2026-10-14): “do not give them alcohol to drink”
24. RNLI (2026-10-14): “It greatly increases your chances of making it through the initial shock.”
25. US National Weather Service (NOAA) (2026-10-14): “Always dress for water temperature, not for air temperature.”
26. RNLI (2026-10-14): “Anything below 15°C is defined as cold water and can seriously affect your breathing and movement, so the risk is significant most of the year.”
27. US National Weather Service (NOAA) (2026-10-14): “Carry an Emergency Position Indicating Radio Beacon (EPIRB), personal locator beacon (PLB) or VHF Radio.”
28. RNLI (Float to Live) (2026-10-14): “Practise floating in a supervised location like a swimming pool.”
29. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “The 1-10-1 Principle is a simple way to remember the stages of cold-water immersion and how long each one lasts.”
30. Transport Canada – Safe Boating Guide (TP 511E) (2026-10-14): “It can take an hour to go unconscious from hypothermia, even in ice water.”
31. US National Weather Service (NOAA) (2026-10-14): “Gasping for Breath & Rapid Breathing (occurs during the first 2-3 minutes or more)”
32. US National Weather Service (NOAA), citing the Red Cross (2026-10-14): “Hot water bottles and chemical hot packs may be used. Wrap the person in a towel or blanket before applying.”
33. US National Weather Service (NOAA) (2026-10-14): “Gasping for a breath or rapid breathing from sudden immersion can be triggered by water as warm as 77°F (25°C).”

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