Tips for handling heat, humidity, and cystic fibrosis

Last updated June 3, 2025, by Roslyn Marano
Fact-checked by Inês Martins, PhD

For people with cystic fibrosis (CF), the combination of CF with heat and humidity can make breathing harder and fatigue worse. Fortunately, there are ways to manage these challenges.

The tips below, organized around key parts of a hot day, offer practical strategies to help you stay safe and more comfortable in the heat.

Morning: Start with airway clearance

Start your day with your prescribed airway clearance techniques. Clearing mucus that accumulates overnight can support better lung function throughout the day. It’s also important to start hydrating early on to help thin mucus and support airway clearance.

The morning can be an ideal time for outdoor physical activity, as lower temperatures and humidity may make breathing more manageable.

Midday: Avoid peak heat

The sun is strongest in the middle of the day — stay indoors or in the shade when you can. If you do go outside, be sure to wear lightweight clothing and bring a water bottle and a cooling towel.

Adjust your schedule so that errands or physical activities are done earlier or later in the day when it’s not as hot. Avoid overexertion during peak heat to prevent extra strain on your lungs and body, which is a common concern when trying to manage CF and heat together.

Afternoon: Rehydrate and refuel

Don’t wait to feel thirsty — by the time you do, you may already be dehydrated. Drink plenty of water and electrolyte beverages throughout the afternoon.

Include salty snacks like beef jerky, snack mix, or salted nuts to help replace the sodium lost through sweat. This helps maintain your energy and caloric intake, while supporting mucus clearance, too.

Evening: Cool down and recover

Evening is a good time to reset. Cool showers, gentle stretching, and relaxing in cooler air can help you wind down.

Doing a second round of airway clearance or exercise can help clear more mucus and prevent germs from growing due to the hot, humid weather.

Lukewarm showers can also loosen mucus, but avoid very hot steam if it aggravates your symptoms.

All day: Monitor and adjust

Throughout the day, watch for signs of dehydration or low sodium, such as:

• dizziness
• fatigue
• headache
• difficulty concentrating
• darker urine
• dry, sticky mouth.

To stay ahead of symptoms:

• Set reminders to drink fluids regularly.
• Take breaks when needed, especially after being outside.
• Use tools like smart bottles or hydration apps to track fluid intake.
• Monitor air quality and adjust your plans if the heat index is high.

Being proactive throughout the day can help protect your breathing and energy levels. With thoughtful planning and a consistent routine, staying active and safe with CF is possible, even in the summer heat.

Cystic Fibrosis News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis, or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.