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What to do in case of a heatwave

  • Last modified date:
    29 June 2009
Man pruning roses

Whilst most of us enjoy sunny weather, the extreme heat of a heatwave can be seriously damaging to the health, and can sometimes be fatal. This article provides information about who is at risk during a heatwave, and advice about what to do in case of a heatwave.

Who is at risk during a heatwave?

Whilst extreme heat is dangerous to everyone it is especially so to babies and young children, older people, those living in care homes, and those in certain at-risk groups.

When temperatures remain abnormally high over more than a couple of days, excessive heat can prove fatal. In one hot spell in London in August 2003, deaths among people aged over 75 rose by 60 per cent.

The Chief Medical Officer, Sir Liam Donaldson has said,

'Although severe heatwaves are uncommon in England, the experience across Northwest Europe in 2003 is a reminder that heat can be fatal, or at the very least can cause unnecessary discomfort.
The elderly are particularly vulnerable and it is important that those aged over 75, especially those who live alone or in care homes, take precautions to avoid heat exhaustion and heat stroke. If you care for people who could be at risk during a heatwave, it's important that you plan ahead - taking action in advance can help reduce the number of excess deaths from heat.'

Those at particular risk during a heatwave include:

  • older people, especially those over 75 years old and living on their own, or in a care home;
  • people suffering from mental ill health, those with dementia, and those who rely on help from other people to manage day-to-day activities;
  • people who are bed-bound or have mobility problems;
  • people taking certain types of medication;
  • people with a serious chronic condition, particularly breathing or heart problems;
  • people who already have a high temperature from an infection;
  • people who use alcohol or illicit drugs;
  • babies and young children, especially under four years old;
  • people who are physically active such as manual workers, or sportsmen and women

What symptoms should you look out for?

In a severe heatwave, extra strain is placed on the heart as it tries to cool the body - this can lead to an increase in heart related illnesses.

Additionally, air quality often gets worse during a heatwave, which can make respiratory symptoms worse. In more extreme situations, one can overheat and dehydrate, leading to heat exhaustion or heat stroke. If you have a heart or respiratory problem, this may make your symptoms worse.

Symptoms of heat exhaustion include:

  • headaches
  • dizziness
  • nausea and vomiting
  • muscle weakness or cramps
  • pale skin
  • a sudden rise in temperature

If you are suffering from worsening of heart or respiratory symptoms or heat exhaustion you should move somewhere cool and drink plenty of water or fruit juice. If possible, take a lukewarm shower, or sponge yourself with cold water. If symptoms are of concern, call NHS Direct or your Doctor.

If heat exhaustion is left untreated, heatstroke can develop, but it can also occur suddenly and without warning.

Symptoms of heatstroke include:

  • headaches
  • nausea
  • an intense thirst
  • sleepiness
  • hot, red and dry skin
  • a sudden rise in temperature
  • confusion
  • aggression
  • convulsions and a loss of consciousness

Heatstroke can result in irreversible damage to the body, including the brain, or death.

Steps to take during a heatwave

Listen to bulletins on radio and television and follow health advice.

Keep out of the heat

  • If a heatwave is forecast, try to plan your day in a way that allows you to stay out of the heat.
  • If possible, avoid going out in the hottest part of the day (11am - 3pm).
  • If you cannot avoid strenuous activity like sport, DIY, or gardening, keep it for the cooler parts of the day such as early morning.
  • If you must go out, stay in the shade. Wear a hat and light loose fitting clothes, preferably cotton. If you will be outside for some time, take plenty of water with you. 

Stay cool

  • If you can, stay inside, in the coolest rooms in the house.
  • Reduce heat form sunlight coming through the windows. External shading, e.g. shutters, is best. Metal blinds and dark curtains may absorb heat and make the room warmer – replace with curtains with white lining to reflect heat.
  • Keep windows closed while the room is cooler than it is outside and open them when the temperature inside rises, and at night for ventilation. If you are worried about security, at least open the windows on the first floor and above, if possible.
  • Take cool showers or baths and splash yourself several times a day with cold water, particularly your face and the back of your neck. A loose, cotton, damp cloth or scarf on the back of the neck can also help you  to stay cool.
  • Indoor and outdoor plants will help keep your home cool due to evaporation and the shading from trees and bushes.
  • Have your loft and cavity wall insulated - this keeps the heat in when its cold and out when its hot.

Drink regularly

  • Drink regularly, even if you do not feel thirsty. Water and fruit juice are best.
  • Avoid alcohol, tea and coffee. They make dehydration worse.
  • Eat as you normally would. Try to eat more cold food, particularly salads and fruit, which contain water.

Help others

  • Older people are much more prone to the effects of heat. You can help older relatives or neighbours by checking on them, if possible, every day, and reminding them to drink plenty and often. They should have a mixture of drinks including fruit juice and water.
  • Help them to keep their house as cool as possible, drawing curtains, opening windows at night, or using a fan if necessary.

When should you seek advice?

Contact your doctor, a pharmacist if you have any unusual symptoms during a heatwave, especially if you are taking medication.

You can also contact NHS Direct on 0845 4647 or visit NHS Direct website for advice.

Watch out for cramp in the arms, legs or stomach, feelings of mild confusion, weakness or problems sleeping.

If you do have these symptoms, rest for several hours, keep cool and drink plenty of water or fruit juice.

Seek medical advice if any of these symptoms get worse or do not go away.

Remember heatstroke can kill. It can develop rapidly and suddenly lead to unconsciousness. If you suspect someone has heatstroke call 999 immediately.

While waiting for an ambulance

If someone is suffering heatstroke and you do need to call an ambulance:

  • Try to move the person to somewhere cooler;
  • Increase ventilation by opening windows and using a fan;
  • Cool them down as quickly as possible by loosening clothes, sprinkling them with cold water or wrapping them in a damp sheet;
  • If they are conscious, give them water or fruit juice to drink;
  • Do not give aspirin or paracetamol.

The Heatwave Plan

As part of its strategy to provide appropriate support and care during a heatwave, the Department of Health updated its heatwave plan for 2009 and its public health information leaflets. The plan’s purpose is to enhance resilience in the event of a heatwave.

Changes have been made to this year’s heatwave plan including: describing the alert levels from level 1-4, but are also given colours to mirror the traffic l ight system; the inclusion of maps and graphs detailing regional patterns during the 2006 heatwave; and additional information on long term planning, including how to create cool environments – in particular for hospitals and care homes.

A central part of the heatwave plan is the 'Heat-Health watch' system which will operate from 1 June to 15 September. The Heat-Health watch will monitor for heatwave threshold day and night temperatures, as well as telephone enquiries to NHS Direct and General Practitioner consultations relating to heat-related illnesses.

The Heat-Health Watch system comprises of four main levels: Green, Amber, Red and Red Emergency. It is based on threshold day and night-time temperatures as defined by the Met Office. These vary from region to region, but the average threshold temperature is 30ºC during the day and 15ºC overnight.

Level 1: Summer preparedness and long-term planning
During the summer months, social and healthcare services need to ensure that awareness and background preparedness are maintained by the measures set out in the Heatwave Plan. Long-term planning includes year-round joint working to reduce the impact of climate change and ensure maximum adaptation to reduce harm from heatwaves. This involves influencing urban planning to keep housing, workplaces, transport systems and the built environment cool and energy efficient.

Level 2: Alert and readiness
This is triggered as soon as the Met Office forecasts that there is a 60 per cent chance of temperatures being high enough on at least two consecutive days to have significant effects on health. This will normally occur 2-3 days before the event is expected. As death rates rise soon after temperature increases, with many deaths occurring in the first two days, this is an important stage to ensure readiness and swift action to reduce harm from a potential heatwave.

Level 3: Heatwave action
This is triggered as soon as the Met Office confirms that threshold temperatures have been reached in any one region or more. This stage requires specific actions targeted at high-risk groups.

Level 4: Emergency
This is reached when a heatwave is so severe and/or prolonged that its effects extend outside health and social care, such as power or water shortages, and/or where the integrity of health and social care systems is threatened. At this level, illness and death may occur among the fit and healthy, and not just in high-risk groups and will require a multi-sector response at national and regional levels.

Further details of the Heatwave Plan for England can be found in the documents in the links section below.

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