FAQ

• What is a heatwave?

  Heatwaves are extended periods (at least 3 days) of hotter than usual weather, where the temperature reaches and remains above average for the time of year and local region. Temperatures must go above a threshold set by the Met Office to be classed as a heatwave.

• How can heatwaves affect our health?

  In heatwaves, it is much harder for our bodies to regulate their internal temperature, leading to a greater chance of heat stress, such as heat exhaustion or heat stroke. Humidity, as well as heat, can decrease the effectiveness of our bodies’ cooling response, as it’s harder for sweat to evaporate from the body.
  The strain on the body as it tries to cool itself can impact organs such as the heart and kidneys and can exacerbate existing health conditions, such as cardiovascular, respiratory, mental health or diabetic conditions. At worst, this can lead to a greater likelihood of organ failure or death, particularly for people who are more vulnerable (children under 5 and adults over 65) or those that have pre-existing health conditions.

• What is heat stress and what causes it?

  Heat stress is the general term used to refer to heat related illness, such as heat exhaustion and heat stroke. Heat exhaustion happens when our bodies work hard to cool down and lose lots of water and salt, typically from sweating. Heat stroke is more serious and this happens when our bodies are no longer able to maintain their normal internal temperature.
  They both have similar symptoms such as tiredness, dizziness, headache, excessive sweating, heat rash, nausea, cramps, fast breathing and heartbeat, high temperatures, being thirsty and feeling weak. These should be treated through cooling and rehydration. If symptoms remain after 30 minutes it’s more likely to be heat stroke and should be treated as a medical emergency (e.g. calling 999, or relevant emergency services in holiday destinations).

• What is the connection between climate change and heatwaves?

  Climate change is resulting in more variable and extreme weather, meaning events like heatwaves are becoming more common and more intense. The record breaking heatwaves in Europe in recent summers were made at least five times more likely due to climate change and UK heatwaves (like in the summer of 2022 where the UK reached 40C for the first time) are now 30 times more likely due to climate change.

• Are heatwaves really more common now compared to the past?

  Yes. Heatwaves are becoming hotter and more common because of climate change. Average global temperatures are higher than in the past, with 2023 the warmest year on record. Europe is the fastest-warming continent in the world, and heat-related deaths have increased by approximately 30% over the past 20 years, due to climate change. Without climate action, this is only going to get worse.

• Why is your campaign focused on Europe and holiday destinations?

  Both Europe and the UK are feeling the effects of climate change and we need to know how to adapt and stay safe in hotter weather, both at home and abroad. 

  The health impacts of extreme heat can be serious and this campaign provides information on how to protect yourself in heatwaves [link to tips], as well as how we can better prepare the UK for hotter weather [link to solutions].

• Why aren’t we seeing more consistently hotter summers in the UK?

  Climate change means our weather is getting more variable and bringing greater extremes – not consistency. So although we may see periods of cooler weather, the heat we get is steadily becoming more extreme.

  June has been cooler due to Arctic winds, but May 2024 was actually the hottest May on record. In June 2022 UK temperatures reached 40 degrees for the first time, and this contributed to approximately 4,500 deaths. The Met Office reports that UK heatwaves are now 30 times more likely due to climate change.

• Who is most affected by heatwaves?

  How individuals are impacted by heatwaves is related to a combination of factors including their health, behaviours and environment. Vulnerable groups include: 

  • Older people aged over 65 
  • Babies and young children under the age of 5
  • Pregnant people
  • People with underlying health conditions

  Older people, young children and pregnant people are all less able to regulate their body temperature, posing a greater risk of health impacts in heatwaves. Sadly, evidence shows that pregnant people who experience extreme heat have a higher risk of birth defects and stillbirth.

  Older people are also more likely to have underlying health conditions which can be exacerbated in extreme heat, particularly cardiovascular, mobility and mental health issues.

• What climate action can we take to address this issue?

  Ultimately, we need to address the root cause of increasing heatwaves – climate change – to protect our health. This involves supporting policies that reduce greenhouse gas emissions across all sections of society to prevent climate change and our temperatures rising. 

  We also need to adapt our environments to cope with the changes we’re experiencing already. Investing in heat adaptation measures like increasing green spaces, providing accessible cooling centres and upgrading buildings will help Britain be better equipped for the heat. Consider reaching out to your local MP if this is an issue you’d like to see action on in your community.