Independent report

Keeping warm or cool in extreme weather - scripts for broadcast media

Published 16 December 2025

The 4 UK Chief Medical Officers (CMOs) as independent advisers provide public health advice in emergencies. To help preparations for the very unlikely scenario of a national power outage, which refers to a total power outage affecting the whole of Great Britain, they have published the public health advice that the public would be given in this scenario.

Many countries plan for a national power outage. This is part of routine resilience and contingency planning for emergencies. A national power outage is listed in the National Risk Register as ‘failure of the national electricity transmission system (NETS)’.

Although a national power outage is unlikely to occur, if it did happen it would result in everyone in the country (except those with backup generators) losing their mains electricity supply instantaneously and possibly without warning. Among other effects this could also result in the loss of:

• mobile and internet telecommunications
• water
• sewage removal and treatment
• fuel
• gas
• ability to make electronic payments

This would cause significant and widespread disruption and risk to health, and the UK CMOs’ advice is to help reduce the public health impact.

The government Prepare website contains helpful, practical advice on how to prepare for a power cut whether it is short lived or on a national scale. See the pages Power cuts and Get prepared for emergencies for more information.

In the unlikely scenario of a national power outage, communicating health advice to the public would be challenging because phone, internet and television services would be disrupted. For this reason, emergency communications to the public would be limited to radio (BBC Radio 2 and Radio 4), which is the most power resilient form of communication. This means that anyone with access to a battery-powered, wind-up or car radio (while the battery lasts) would be able to access the advice. 

Specifically, the UK CMOs have developed scripts to provide public advice on the following important health topics in the unlikely event of a national power outage:

• water and sanitation
• food and nutrition
• keeping warm or cool in extreme weather

For water and sanitation, and food and nutrition there is a shorter version of the script to be read on the first day of the emergency and a more detailed version for the following days. These 2 scripts are considered by the UK CMOs to cover the most important health topics, due to the urgency of providing accurate advice to the public early on in the emergency. Keeping warm or cool in extreme weather is intended to be helpful in certain situations in winter or summer. 

These are not government policy - they been developed by the 4 UK CMOs as independent health advisers, with valuable input from the UK Health Security Agency (UKHSA) and collaboration across the 4 nations and their respective public health agencies.

Script: extremely cold weather during a national power outage

[For use when the temperature gets to −2 degrees.]

A public health message from the UK Chief Medical Officers - please listen carefully. 

Hello, this is [insert name], Chief Medical Officer/other for [insert nation]. I am about to provide you with important information. You may want to write this down so that you can refer to it later. We will be repeating this advice regularly.

We have planned in case this extraordinary situation happened and this advice has been created by doctors and scientists to help keep you and your family healthy. 

Some parts of the UK are currently experiencing extremely cold weather. In this broadcast, I am going to provide you with information on how to stay safe during this time. 

During this time there are things you can do to keep warm. For most people cold weather will be inconvenient but not dangerous, however cold weather can cause serious health problems for some groups. Babies, young children, pregnant women, older people and people who need care are at particular risk from cold weather. If you are in one of these groups or look after someone who is, you should pay particularly close attention to this advice. 

Stay inside as much as possible. Only leave your home if you have to. 

You are advised to wear several thin layers of clothing and wrap up warm. While you are sitting, keep your feet raised because air near the floor is colder. Get up and move around and stretch at least every hour. Get everyone in the house to gather in one room to share warmth. Put something like a towel or sheet under the doors of the rooms you are using to reduce draughts. Close your curtains and blinds when it gets dark to help keep the heat in. Use blankets or sheets to cover your windows if you don’t have curtains or blinds. Close the windows and doors in rooms you are not using. 

Becoming very cold can have serious effects on your health. Look out for the signs of hypothermia in people in your home. You are looking for shivering, cold and dry skin, skin and lips that are blue or grey (which may easier to see on the palms of the hands or the soles of the feet of black or brown skin), slurred speech, slow breathing and appearing tired or confused. 

A baby with hypothermia may be cold to touch, floppy, unusually quiet and sleepy, and may refuse to feed.

If you think someone has hypothermia, take the following steps:

• move them indoors or somewhere sheltered as quickly as possible
• remove any wet clothes and wrap the person in a blanket, sleeping bag or dry towel, covering their head
• if they are awake give them some sugary food like chocolate and a warm non-alcoholic drink
• stay with them and keep them awake by talking to them
• get medical help if you are able to

There are some things you must not do to keep warm as they are dangerous. Do not light a fire indoors unless you have a proper heating appliance for this purpose or a fireplace with a working chimney. Do not use camping stoves and barbecues indoors as there is a risk of carbon monoxide poisoning, which can kill. Do not use petrol or diesel generators or other similar fuel driven equipment indoors as the exhaust gases contain carbon monoxide.

You may have some other ways of keeping warm. Be very careful when using heating appliances that are not mains powered. If you have a portable gas heater that uses gas bottles and is approved for indoor use, make sure the room is well ventilated and follow all instructions carefully as the fumes can be dangerous.

If you have a generator, place it outdoors at least 6 metres or 20 feet away, with the exhaust facing away from windows or doors. 

If you have a wood burner or other non-electric stove, make sure the room is well ventilated and follow all instructions carefully to avoid carbon monoxide poisoning. Never leave a fire, portable heating appliance or generator unattended and keep a fire extinguisher nearby. 

Only use the recommended type of fuel for heating appliances. Do not burn old furniture, pallets or fence panels, household rubbish or fuels such as petrol, diesel or lighter fluid as this could cause an explosion, fire or release of harmful chemicals.

We encourage you to look out for your neighbours, friends and family members who may be struggling at this time.

Please follow this advice until you hear otherwise to give everyone the best chance of staying as healthy as possible through all the disruption. We will be repeating this advice regularly.

Script: extremely hot weather during a national power outage

[For use when the temperature hits 38°C or higher.]

A public health message from the UK Chief Medical Officers - please listen carefully. 

Hello, this is [insert name], Chief Medical Officer/other for [insert nation]. I am about to provide you with important information. You may want to write this down so that you can refer to it later. We will be repeating this advice regularly.

We have planned in case this extraordinary situation happened and this advice has been created by doctors and scientists to help keep you and your family healthy. 

Some parts of the UK are currently experiencing extremely hot weather. In this broadcast, I am going to provide you with information on how to stay safe during this time. 

During this time there are things you can do to keep cool. For most people hot weather will be inconvenient but not dangerous, however hot weather can cause serious health problems for some groups. Babies, young children, pregnant women, older people and people who need care are at particular risk from hot weather. If you are in one of these groups or look after someone who is, you should pay particularly close attention to this advice. 

You should make sure you keep hydrated and drink at least 2 litres of liquid per day which is approximately 8 cups. When it is extremely hot, you are at increased risk of dehydration so it is even more important to try to drink enough fluid. Advice on how to make other sources of fluid safe to drink is being provided in other broadcasts.

Keep your home cool by closing windows, blinds and curtains that are in direct sunlight during the day. Close external shutters or shades. Only open your windows when the air feels cooler outside than inside, for example at night, to increase air flow through the home.

Sit and sleep in the coolest part of the home. 

If you have to go outside, for example to collect water, food or to check on others, do this at cooler times of the day. 

It is important to look out for the signs of heat exhaustion in people in your home. This happens when the body overheats and cannot cool down. Common symptoms of heat exhaustion include tiredness, weakness and feeling faint, headache, muscle cramps and feeling or being sick, heavy sweating or feeling very thirsty.

Heat exhaustion can lead to heatstroke. Common symptoms of heatstroke include confusion, clumsiness, fast heartbeat, fast breathing or shortness of breath, hot skin and seizures. 

If you think someone in your home has heatstroke or heat exhaustion, take the following action. Move them indoors or to somewhere in the shade. Remove any extra clothing like jackets or socks. Give them water, a fizzy drink or some other fluid to drink. Spray or sponge them with cool water. You don’t need to use clean water for this. Do not use the water that you have made safe to drink.

They should start to cool down and feel better within 30 minutes. If there is no improvement in this time or their symptoms are getting worse, try and get medical help, if you can.

We encourage you to look out for your neighbours, friends and family members who may be struggling at this time.

Please follow this advice until you hear otherwise to give everyone the best chance of staying as healthy as possible. We will be repeating this advice regularly.

Script: for use only if flooding

If you have been in contact with flood water or sewage, immediately wash your hands using water that has been prepared for handwashing. Do not use flood water for drinking.