Hydrotherapy Warning Signs Checklist: When to Get Out and When to Call for Help

Urgent first

Call emergency services right away for any of these. In the United States call 911. The NHS (UK) uses 999 and 111 for the same situations.

• Someone is not breathing, cannot be woken, or is slumped in water.
• Chest pain that feels tight or like squeezing, or pain spreading to the arm, neck or jaw [1].
• Signs of heatstroke: very high temperature, hot skin without sweating, fast breathing and heartbeat, confusion, seizure or loss of consciousness [2].
• Suspected hypothermia: the NHS calls it a medical emergency [3].
• Shaking or jerking (a seizure) [4].

Poison Help (US) is 1-800-222-1222 for chemical exposure. Information only; this page is not a substitute for medical care.

How to use this list

This is a checklist of signs, not a plan for pushing limits. We give no safe time or temperature. The hot-tub death review recommends people be aware of warning signs that warrant immediate cessation of hot tub use [5]. If you are unsure, get out of the water, with help if you feel unsteady, and ask someone to stay with you.

Signs to get out and sit somewhere cool

The NHS says heat exhaustion usually does not need emergency help if you can cool down within 30 minutes, but it can turn into heatstroke [2]. Cool the person's skin and give water, as the NHS describes [2]. For details see heat illness, dehydration and overheating.

Signs that call for emergency help

• Fainting. The NHS says call 999 if someone is not breathing, cannot be woken within 1 minute, has chest pain or palpitations, hurt themselves, shakes or jerks, or fainted while lying down [4].
• Heatstroke. Still unwell after 30 minutes of resting in a cool place and cooling, or confusion, seizure or collapse [2].
• Hypothermia. Shivering, pale cold skin, slurred speech, slow breathing, tiredness or confusion. The NHS says not to use a hot bath to warm the person and not to give alcohol [3].
• Heart attack. Squeezing chest pain, severe breathlessness, pale blue or grey skin [1].

Signs after you leave the water

• Cough, fever, chest pain or shortness of breath within about two weeks of using a hot tub or spa: may be Legionnaires' disease. Say where you have been [6]. See Legionella in hot tubs.
• Itchy red rash with pus-filled bumps: see hot tub rash. Skin that is painful, hot and swollen needs urgent advice [7].
• Fainting at any time: the NHS says see a GP even if it seems minor [4].

Cold water

Cold shock, cold incapacitation and swimming failure are covered on our temperature exposure safety page and cold-water swimming safety. We could not read the RNLI page (access error), so we do not give cold-shock details here; the NHS lists falling into cold water as a cause of hypothermia [3].

People who should check with a clinician first

Heart conditions, blood pressure problems, pregnancy, epilepsy, diabetes or reduced sensation, kidney disease, and certain medicines: see preparing for hydrotherapy. The NHS says children, older people and people with long-term conditions such as diabetes or heart problems are at higher risk of heat illness [2].

Do not

• Do not soak without someone nearby, as the reviewers advise supervision of vulnerable people, and do not mix alcohol or drugs with heat [5]; see alcohol, drugs and hydrotherapy.
• Do not push through symptoms.
• Do not drive yourself to hospital if the NHS advice says to call an ambulance [2].