Hot weather can be uncomfortable for anyone, but it can be especially difficult if you have aspergillosis, asthma, bronchiectasis, COPD or another long-term lung condition. Heat can make breathing feel harder, disturb sleep, worsen tiredness and, in some people, contribute to dehydration or a flare-up of respiratory symptoms.
A little planning can make hot days safer and more manageable.
Why heat can affect breathing
When it is hot, your body works harder to keep cool. This can increase your heart rate and make you feel short of breath or exhausted more quickly. Hot, humid or polluted air can also irritate sensitive airways. Some people find that pollen, smoke or poor air quality add to the problem.
People who are older, have heart or lung disease, take several medicines, or have limited mobility may be at greater risk of becoming unwell in hot weather.
Keep cool at home
- Close curtains or blinds in rooms facing the sun during the day.
- Keep windows closed when the air outside is hotter than indoors; open them later in the evening or overnight if it is safe to do so.
- Move to the coolest room in the house, especially during the hottest part of the day.
- Use a fan to improve comfort, but remember that a fan does not lower the room temperature. Cool your skin too, with a cool shower, damp cloth or spray of water.
- Wear loose, lightweight clothing and use light bedding at night.
- Turn off lights and electrical equipment that are not needed, as these can add heat.
Drink regularly
Have regular cold drinks throughout the day, even if you do not feel very thirsty. Water is a good choice; cold foods with a high water content can help too. Limit alcohol, which can contribute to dehydration.
If a clinician has told you to restrict fluids because of heart, kidney or another health condition, follow their advice rather than increasing your intake.
Plan outdoor activity carefully
- Try to avoid the hottest part of the day, usually from 11 am to 3 pm.
- If you need to go out, seek shade, wear a hat and take water with you.
- Move exercise, walks and essential jobs to early morning or later evening.
- Check the weather forecast and air-quality information. On days with high pollution, smoke or pollen, staying indoors may be more comfortable.
- Take your usual inhalers and other essential medicines with you.
Medicines and hot weather
Continue to take prescribed medicines as directed. Do not stop or change medicines because of the weather without speaking to your pharmacist, GP or specialist team. Ask a pharmacist if you are unsure how to store a medicine during hot weather, as some treatments should not be left in a hot car or direct sunlight.
If you use an inhaler, nebuliser, oxygen or airway-clearance equipment, make sure you have the supplies you need before a period of hot weather begins.
Air conditioning and fans
Air conditioning can make a room more comfortable and can reduce indoor humidity. However, units that become damp, dirty or poorly maintained can support mould growth. If you use air conditioning, follow the manufacturer’s cleaning and maintenance instructions, empty or drain portable units as directed, and arrange servicing where needed.
Read more: Air conditioning units and mould: what people with aspergillosis should know.
Know when to get help
Heat exhaustion can cause tiredness, dizziness, headache, nausea, heavy sweating, cramps, thirst or weakness. Move to a cool place, drink cool fluids if you can, cool your skin and ask someone to stay with you.
Call 999 if someone is confused, collapses, has a seizure, is very hot and unwell, or does not improve quickly after cooling down.
Seek urgent medical advice if your breathlessness is substantially worse than usual, you have chest pain, blue or grey lips, new confusion, or your usual rescue treatment is not helping. For non-emergency urgent advice in England, call NHS 111.
Prepare before a heatwave
- Keep drinks, easy cold food and regular medicines available.
- Make sure someone knows to check in on you if you live alone or are likely to struggle in the heat.
- Keep your care plan and important contact numbers accessible.
- Watch for UKHSA and Met Office Heat-Health Alerts during warmer weather.
For current general advice, see the NHS guide to coping in hot weather and UKHSA guidance on staying safe in hot weather.
Reviewed: September 2026
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