Immediate danger to life: call 999 or 112.
UK Ready is an independent information site. Current official instructions for your area take priority over this general guidance.
Sources checked 13 October 2026
Move to a cooler safe room, reduce unnecessary exertion and shade sun-facing windows. Open windows for cooling only when outside air is cooler and it is safe to do so. An active chemical or radiation sheltering instruction takes priority over ordinary ventilation advice. Seek a safer cooled place through appropriate local arrangements if the home cannot remain safe.
Drink suitable safe fluids and follow any individual fluid restriction or care plan. Older people, babies, children and people with relevant health conditions need particular attention. Do not leave anyone or a pet alone in a stationary vehicle. Do not cover a pram with material which traps heat and restricts airflow.
Avoid strenuous activity during the hottest part of the day. Plan care, dog walking and necessary travel for cooler conditions where possible. Keep temperature-sensitive medicines within product requirements and obtain pharmacist advice if storage fails.
If someone has heat exhaustion: Move them to a cool place, remove unnecessary clothing and cool their skin with water and airflow where safe. Give safe fluids if they are conscious and can swallow, and follow NHS guidance. Do not give a drink to someone who is unconscious or cannot swallow safely.
Possible heatstroke: Confusion, a seizure, collapse, loss of consciousness or severe illness in the heat requires emergency help. The NHS also advises calling 999 if a person remains unwell after 30 minutes of cooling and rest. Start cooling while help is coming and follow the call handler. Do not wait for that period if serious warning signs are already present.
Electric fans depend on power and are not a complete solution to extreme heat. Follow current UKHSA advice about when they can be used safely rather than generating a universal temperature rule from a consumer product guide.
During a simultaneous water outage: Obtain safe fluids early, prioritise people with greater needs, and seek support if you cannot keep someone safely hydrated or cool. Household water-planning quantities are not individual treatment advice.