Environmental Health:

Heat & Humidity

Did You Know?

When you are exposed to extreme weather conditions, such as extreme heat and humidity, your body must use extra energy to try and cool down.

Heat and humidity can affect your breathing, especially if you have asthma or COPD.

On very hot, humid days, especially days that have high levels of air pollution or smog, stay indoors. Find an indoor place that’s cool. Make sure the place you choose has clean air – this means no tobacco smoke or harsh scents.

If your home is not air conditioned, go to an air-conditioned public space, like a recreation centre, public library, or shopping mall.

Heat and COPD

How heat can affect your COPD: Your body is always working to maintain a normal body temperature. When you are exposed to extreme weather conditions, such as extreme heat and humidity, your body must use extra energy to try and cool down. This extra energy causes your body to work harder.

If you have COPD, you are already using much of your energy just to breathe. When you are in extreme heat your body uses more energy while working hard to keep your normal body temperature. If it gets too hot, this can affect a person’s breathing.

Know the signs of a COPD flare-up:

It is important for people with COPD and their caregivers to understand the warning signs of a COPD flare-up (times when COPD symptoms get a lot worse.) Learn how to treat and prevent them. Signs of worsening COPD could include increased shortness of breath, as well as increased coughing and sputum (phlegm or mucus).

If you notice any of these symptoms, follow the advice in your COPD action plan. If you don’t know what to do or if your symptoms are getting worse, call your doctor.

If you can’t reach your doctor, go to the hospital emergency department.

Heat and Asthma

Many people with asthma, experience asthma flare-ups in times of high heat and humidity. Extreme temperature can cause air to become stagnant (not move), trapping pollutants in the air, which can also cause an asthma flare-up.

Did You Know?

The Air Quality Health Index or “AQHI” is a scale designed to help you understand what the air quality around you means to your health.

Some things to remember when it is hot and humid:

  • Stay indoors in an air-conditioned place with good indoor air quality.
  • Keep your windows and doors closed to keep your house cool and keep pollutants out. Keep your curtains and blinds drawn to keep out the heat.
  • Turn on fans. At night, if you don’t have air conditioning and there are low levels of air pollution outdoors: open your window to let the cooler air in.
  • Keep your rescue medicine (usually a blue puffer) with you, take your medication regularly.
  • Avoid strenuous activities, hard work and reduce the amount (or length of time) of exercises during these times.
  • Check the AQHI
  • Listen to air quality and humidity (humidex) advisories.
  • Know your warning signs of a flare-up.
  • Know the signs of heat stroke and when to see your doctor.
  • Drink plenty of water.
  • Wear loose, cool, and light-coloured clothing and a hat if you go outdoors.
  • Avoid exercise, especially during the hottest time of the day (generally between 11:00 AM and 3:00 PM)
  • Make sure someone checks up on you if you are living alone.

Learn more about Indoor Air Quality, Outdoor Air Quality, and the human health effects of Climate Change.

Page Last Updated: 28/02/2023