Q&A: heatwave health
Today, several news sources reported the dangers of Britain’s soaring temperatures, which are set to hit 32°C later in the week. It has also been reported that thick clouds are likely to trap in the heat and humidity of the day, making temperatures uncomfortably high at night.
The coming week has been given a level two health warning by the Met Office. There has been some speculation that, if temperatures continue to rise, an emergency level four situation could be declared. According to The Sun, the summer of 2009 has been predicted to be the hottest summer ever, smashing Britain’s 38.5°C record, which was set in the heatwave of 2003. This means that hospitals need to be on standby for high numbers of people with heatstroke, exhaustion and dizziness. The last major heatwave in the summer of 2003 was linked to the deaths of more than 2,000 people.
What are the dangers of the heat?
Although many people enjoy hot weather, it is sometimes be associated with illness or even death. The main short-term dangers are dehydration from not drinking enough water, heat exhaustion and heatstroke.
- Dehydration occurs when the body’s water content is reduced. It can prevent the body’s systems from regulating themselves and can cause a number of complications.
- Heat exhaustion occurs when the body’s temperature rises to between 37°C and 40°C, causing nausea, faintness and heavy sweating.
- Heatstroke sets in if the body’s temperature rises above 40°C, preventing the cells and body systems from functioning normally. Those affected may develop rapid breathing, headaches, lethargy, confusion and even loss of consciousness. Unless emergency treatment is given, it can result in multiple organ failure and death.
There were 2,139 deaths in the heatwave of August 2003, although the number of cases of heat exhaustion is not known as people do not always seek medical help.
Who is most at risk from the heat?
While everyone is at risk of dehydration, heat exhaustion and heatstroke, certain groups are more at risk. These include the elderly, infants and young children, those with existing chronic medical conditions (such as heart or respiratory problems), people with mobility problems, and those who abuse drugs or alcohol. People who are normally fit and healthy can also raise their risk by exerting themselves in the heat, for example by taking part in sports or athletics.
Everyone should be aware of the risks of skin cancer and how to keep safe in the sun. There is an increased risk of skin cancer in people with fair skin who burn easily, those with many moles or freckles, people with fair hair and light-coloured eyes, and those with a family history of cancer.
What about the risk of skin cancer?
Exposing the skin to excessive UV (ultraviolet) light (found in sunlight) is the main cause of most types of skin cancer. Skin cancer is now one of the most common cancers in the UK, with 10,400 cases diagnosed annually. There are two types of serious skin cancer: malignant melanoma and non-melanoma skin cancers (such as squamous cell and basal cell carcinoma).
Melanoma often shows up as a change in colour, size or shape of a mole. The cancer is aggressive and requires early detection and urgent treatment. The incidence of malignant melanoma is said to be four times greater today than in the 1970s, making melanoma the fastest rising cancer in the UK.
Non-melanoma skin cancers are more common and can be treated more easily. Basal cell carcinoma usually appears as a slow-growing, round, pearly-coloured lump, while squamous cell carcinoma (the more serious of the two) may vary in appearance from a scaly lump to a sore or ulcer.
What can I do to keep safe in the sun?
Always ensure that you stay hydrated by keeping water with you and drinking regularly. Try to avoid alcohol and caffeinated drinks, which can dehydrate you further. Choosing cool foods, such as salads, may also help. It is best to avoid excessive physical activity, particularly in the hotter periods of the day. If you become too hot, running cool water over your hands, wrists and feet and splashing your face can cool you down.
Wherever possible, it is best to avoid the sun altogether and remain in the shade between the hours of 11am and 3pm, when the sun’s UV rays are at their most intense. Keep rooms cool by keeping the windows covered with pale-coloured curtains, material or blinds. Keep windows closed when the outside temperature is higher than that indoors, although it should not be a problem to open them at night when the temperature is cooler.
Exposed skin should be covered with sunscreen, at least SPF 15. Apply liberally 15 to 30 minutes before going out in the sun. Reapply every two hours or more frequently if you’re going in the water (even if the sunscreen is said to be waterproof) or you’re sweating. Cancer Research UK advises reapplying sunscreen even if the sunscreen claims to need only one daily application. You can also take measures to cover up as much as possible, for example by wearing cool, loose clothing (close weave is advised) and a wide-brimmed hat.
Cancer Research UK also warn that clothes stretch when wet and allow more UV radiation to penetrate the material. People should be aware of this when swimming in a T-shirt to try and block out the sun. You can burn even when it is cloudy.
Sunglasses are important as UV light can damage the eyes and delicate skin around the eyes. Cancer Research UK recommend sunglasses with a ‘CE’ and ‘British Standard’ mark and which state that they offer 100% UV protection and carry a UV 400 label.
Weather conditions can intensify quickly, so keep an eye on the forecast and plan ahead to avoid the heat.
How should I protect my children?
Babies and young children are particularly at risk from the dangers of hot weather and the sun. All the heat advice for adults applies to children, but they should be closely monitored because they are more vulnerable than adults. Measures to follow include:
- keeping children, particularly babies, out of direct sunlight as much as possible,
- placing them in the shade or preferably in a cool room indoors,
- giving them plenty of water to drink to prevent dehydration, and
- protecting their delicate skin with clothing and sunscreen.
While babies with fair skin and hair and pale eyes are most at risk, all babies have delicate skin that is easily damaged. It is particularly important to ensure that babies and young children wear sunscreen (formulated for young skin), protective loose clothing, sunhats, sunglasses and that they stay in the shade as much as possible. Parents should also be aware of the need for these precautions when sending their young children to school or nursery.
Although skin cancer is reportedly rare in young children, damage to young skin may lead to the development of skin cancer later in life. It is a good idea to make children familiar with good sun-protection habits as they are more likely to use them in the future.
What shall I do if I become ill?
Heat exhaustion and heatstroke require prompt treatment to prevent complications. People with suspected heat exhaustion should be kept cool and given plenty to drink, which should lead to a quick recovery without any remaining ill effect. They should avoid the sun and heat as much as possible and drink plenty of water to prevent further heatstroke.
If heat exposure persists and the person becomes confused, it means that heatstroke is developing and urgent medical treatment is required. The emergency services should be contacted and the person will need to be transported to hospital. NHS figures report that 90% of people with heatstroke will survive if they receive rapid treatment, but if this is not administered the survival rate can be as low as 20%, particularly among vulnerable people such as children or the elderly.
What are the signs of skin cancer?
Over-exposing skin to sunlight increases the risk of developing skin cancer, so protecting the skin is vital. You should be aware of the moles on your skin and their appearance, not just in the summer but all year round. Be alert to any changes in:
- Colour: this may not necessarily be a colour change all over, but differences in pigment in different areas of the mole.
- Shape: particularly changes in the border, for example if the edge becomes blurred or irregular.
- Size: for example, a mole that seems to be growing and any irritation, itching, bleeding or crusting of the mole. If you have any concerns about a mole, consult your GP immediately.
What does the current level two alert mean?
A level two alert means that the Met Office has advised that a heatwave is imminent and there is a 60% chance that temperatures over the next few days could pose significant health risks. The guide available through the NHS Choices website advises you to be prepared for hotter weather and to take precautions to make sure that you stay cool, well hydrated and out of the sun as much as possible. You don’t need to take any other immediate action.
If a level three alert is declared in the coming days or weeks, this means that heatwave temperatures have been reached in areas of the UK. At this point, people are advised to:
- avoid unnecessary travel,
- stay inside wherever possible in the coolest room in the house with the windows kept closed,
- stay in contact with vulnerable people to make sure that they have all they need, and
- be aware of the risks and symptoms of heat exhaustion and heatstroke.
Links to the headlines
‘Killer heat’ warning. The Sun, June 29 2009
Week-long heatwave set to hit UK. BBC news, June 29 2009
Weather warning for Britain with temperatures set to soar. The Times, June 29 2009
Red hot alert. Daily Mirror, June 29 2009