Your health during extreme weather

Preparing for emergencies

With our climate changing rapidly, extreme weather events are becoming increasingly common. The heatwave of 2018 was the worst in living memory, but a heatwave at least this bad is now expected every 1 in 4 years, and this frequency will rise to 1 in 2 years within two decades.

It’s important you have preparations in place at home, and that you follow the information from the local NHS and government when events occur.


Heatwaves can be due to high daytime temperatures, or when the temperature fails to drop low enough at night.

Whilst most people enjoy a bit of sunshine, a heatwave is different, and periods of extreme heat can kill 1000s.

For advice on what to do during a heatwave, visit our dedicated advice page.

When temperatures rise, it places a strain on the body’s vital organs, particularly the heart and lungs. The main causes of illness and death are respiratory and cardiovascular diseases. People who have other medical problems or are very young or very old are at increased risk.

Medicines that you or your child use to manage their condition can also be damaged by high temperatures, and can stop working.

Extreme heat can also affect the services you rely on. Road and rail transport, water and electricity supplies, and the availability of essential emergency services, can all be disrupted. Hospitals will be busier than usual.

A woman looks out of the window of her car looked stressed whilst stuck in traffic

It’s vital you are prepared.

Download the national ‘beat the heat’ checklist to make sure you’re ready.

Heatwave alerts

Table of heat wave alerts level 1 to 4

Guidance to follow during heatwaves

During a heatwave, we recommend you follow the national public health advice .

You can find our more from the Met Office about extreme hot weather.

Extreme winter weather and cold

As well as extreme high temperatures, we also experience periods of very cold weather, which can be equally dangerous to health.

Snow and ice can also bring significant disruption to transport, water and power systems, affecting your supplies of foods and medicines, and your ability to keep your home warm.

A similar alert system exists for severe winter weather alerts.

table outlining the different levels of extreme winter weather warnings

Read our guide for advice on how to prepare for extreme winter weather, and what to do when it happens.

If you’re coming to the hospital during periods of bad winter weather, allow extra time for your journey.

Harmful air quality and pollution levels

Air quality has short- and long-term effects on our health.

DEFRA publish a daily air quality index (DAQI) which can help you decide how you can protect yourself against exposure on days when air quality is particularly bad.

You can check the air pollution forecast here.
An infographic shows the effects of air pollution from pregnancy to the elderly

It is not always possible to predict in advance who will be affected, but you should be prepared, particularly if you have experienced problems in the past, or don’t know how poor air quality affects you.

You are particularly at risk if you have lung or heart conditions. When air pollution is bad, you are at increased risk of becoming ill and needing treatment.

Older people are more likely to suffer from lung and heart problems, so it makes sense for them to be cautious. Children can also be more vulnerable; for example, children with asthma may notice they need to increase their use of reliever medication.

Local air quality is very hard to predict, so you may still experience symptoms when the forecast is good based on particularly conditions (such as a vehicle idling near where you are working).

The Daily Air Quality Index is graded from 1 (low pollution) to 10 (very high pollution);

table of air pollution rates

For more advice for what you can do when air quality is very poor, or to protect yourself from exposure to harmful airborne pollution, visit our dedicated response page.