Web traffic to Macmillan’s heatwave advice for people with cancer soars 300% as high UK temperatures continue

Anthony Cunliffe, Lead Medical Adviser at Macmillan Cancer Support, said:

“While hot weather can affect everyone, heatwaves can be particularly dangerous for people living with cancer. Cancer and its treatment can make it harder for the body to cope with extreme heat, increasing the risk of dehydration and other complications.

“For people currently receiving treatment, dehydration can have a much greater impact than many realise, particularly on kidney function, and this may not always cause obvious symptoms straight away. Some cancer treatments, including certain systemic anti-cancer therapies and radiotherapy, can also make skin more sensitive to the sun, increasing the risk of sunburn and skin damage.”

“With temperatures remaining high and additional heatwaves likely, it is critical that people living with cancer take extra precautions to stay cool and well hydrated. For anyone concerned, there’s plenty of information and advice on the Macmillan website or for someone to talk to, call our Support Line where you can speak to a nurse, open 7 days a week.“

Fact box

• Data for the last four weeks (16th June 2026 – 13th July 2026) shows just over 1,700 views of Macmillan’s ‘tips for coping in a heatwave’ webpage, compared to around 400 views for the four weeks previously (which included the May UK heatwave) – a rise of more than 300%[i]
• In first four weeks after the webpage was first published in 2025, it had just 136 views – showing a stark and increasing need for this guidance in the most recent hot weather

1. Try to keep your home cool
   Most houses in the UK do not have air conditioning. There are still ways you can help to keep the temperature down at home.
   It can help to keep your windows and blinds closed during the day. You can then open them in the evening once the outside temperature feels cooler than the inside temperature to let in the colder air.
   Using a fan will not reduce the air temperature but it can help you feel cooler if the temperature is less than 35C. You should not aim the fan directly at yourself, because it means sweat will evaporate more quickly. While evaporation is what cools you down, it also means you lose water more quickly and if you don't replace that water by drinking enough fluids, you can become dehydrated.
   Public spaces, such as shopping centres and libraries, often stay cooler than our homes, and some even have air conditioning. You can make use of these spaces to stay cool.
   The Government website has more tips on 40.
2. Adjust your routine to stay cool
   The heat can intensify some common side effects of cancer and cancer treatment so it is important to be aware of this. You may feel more tired than usual, and be more likely to feel other effects of the heat such as dizziness and dehydration.
   Try to adjust your routine to help you keep cool. You may need more rest than usual. Plan essential activities and chores for cooler parts of the day if you can. Try to stay in the shade during the hottest parts of the day. Usually this is between 11am and 3pm. You can also try taking cool, but not cold, showers.
   The Macmillan website has further information on coping with treatment including chemotherapy side effects and radiotherapy side effects.
3. Stay hydrated
   Cancer and side effects of cancer treatment can make you become dehydrated more quickly. During hotter weather you may need to drink more than you usually do to stay hydrated. You may also find that you do not feel like eating as much.
   Try to eat and drink cold things and avoid anything which might increase dehydration, like caffeine, alcohol and salty foods unless advised otherwise. You might want to try to eat lighter, more regular meals to make sure your body is getting the nutrition it needs.
   The Macmillan website also has more information on healthy eating and cancer, and how cancer can affect eating.
4. Protect your skin
   Some cancer treatment can make all skin types more sensitive to the sun. You might get sun burnt more easily than you did before, or be at a higher risk of developing skin cancer.
   You can protect your skin by staying in the shade, covering up, and using high factor sun cream.
   We have more information on sun safety and cancer treatment.
5. Seek advice if you feel unwell
   If you feel unwell during the heatwave it is important to speak to a doctor. This is because people who have cancer are more at risk of developing heat exhaustion and heat stroke.  The NHS website has more information about heat exhaustion and heat stroke.
   If you or someone else has symptoms or you need advice you can call NHS 111 or get help from NHS 111 online.

[i] Macmillan Cancer Support internal data. Google Analytics 360 platform. From 16th June to 13th July 2026, the page macmillan.org.uk/cancer-information-and-support/stories-and-media/blogs/hot-weather-and-cancer had 1,706 views, compared with 409 from 19th May to 15th June 2026. In the four weeks after it was first published (17th July 2025 to 14th August 2025), it had 136 views. Figures correct as of 18:30 on 14th July 2026.