London Ambulance Service issued the reminder on 30 April 2025, saying forecasters expected May Day temperatures could be the warmest so far in 2025. Senior paramedics asked Londoners to stay safe and to call 999 only in a life-threatening emergency1.
The service said it had taken around 6,000 calls to 999 every day since Sunday, an additional thousand calls a day compared with the same period last month. It said the warm spell coincides with a bank holiday weekend which also sees 999 call volumes increase when people are unable to access the usual healthcare support1. Alison Blakely, Deputy Chief Paramedic and Gold Commander at London Ambulance Service, said the service had taken action to reduce any adverse impact, "such as extra ambulance crews out on the road and additional call handlers in our control rooms"1.
The service said it was prepared for an increase in calls about difficulty in breathing, dizziness and fainting, and more calls about chest pains and heart problems. It said older people, the very young and people with pre-existing conditions are more at risk in hot weather1.
"Older people, the very young and people with pre-existing conditions are more at risk in hot weather, so please look out for neighbours, family or friends who may need some help and make sure they are able to keep cool during the heat."
The service's advice, as published, is set out below.
| Topic | Advice given by London Ambulance Service1 |
|---|---|
| Sun exposure | Avoid prolonged exposure to direct sunlight, especially between 11am and 3pm when UV rays are at their strongest; stick to shade and wear sun cream |
| Fluids | Drink plenty of water; take a bottle of water when heading out |
| Alcohol | Be sensible; make sure you have a meal and try to have soft drinks as well |
| Medication | Make sure you have the medication you need before the bank holiday weekend |
| Pharmacies | Use the NHS pharmacy finder to check which pharmacies are open near you in London |
| Contacting services | Contact your GP, pharmacy or NHS 111 where possible |
Why it matters for households
The warning covers London over the May Day bank holiday, with the service reporting sustained demand on 999 since Sunday1. It asks people to use the service wisely and to contact a GP, pharmacy or NHS 111 where possible, and to check which pharmacies are open using the NHS pharmacy finder1. Households can read our guides on when to call 999 or NHS 111 for heat illness, when to call 999 and when to call 111 and when to call 999. More background is in our heatwaves and drought hub, staying informed hub and health emergencies hub.
The service also asks people to look out for neighbours, family or friends who may need help keeping cool, and to make sure they have the medication they need before the bank holiday weekend1.
What happens next
No further dates or updates have been reported. The service's advice applies to the bank holiday period covered by its 30 April statement1.
Calling 999 for Heat Illness
When to Call 999
When to Call 111 or 999
