UKHSA heat-health alerts issued for most of England

The UK Health Security Agency had a Level 3 Heat Health Alert in place for southeastern areas in the week of 11 July 2022, with a Level 2 alert for much of the rest of England, the Met Office reported on 12 July 2022¹. NHS England issued its own heat-health watch alerts for parts of England, including a Level 2 alert issued at 9:30am on Thursday 7 July 2022 and a Level 3 alert issued at 8:34am on Friday 8 July 2022².

The Met Office said heatwave criteria, when specific temperature thresholds must be exceeded three days running, would be met for many locations in southern and central England and Wales early that week¹. Temperatures on Tuesday 12 July could peak at 31°C in the southeast, with slightly less hot conditions on Wednesday and Thursday when temperatures were more likely to peak in the high 20s Celsius¹. A persistent area of high pressure over the southern half of the UK was responsible for the warm spell, bringing largely dry and clear weather with little cooling into the evenings¹.

The Met Office extended an Amber Extreme heat warning for Sunday 17 July and Monday 18 July, saying temperatures could be in excess of 35°C in the southeast and more widely around 32°C within the warning area¹. It said the warning highlighted likely adverse health effects for the public, not just limited to those most vulnerable to extreme heat, and that an extension would be considered in the coming days¹. The record high temperature in the UK is 38.7°C, reached at Cambridge Botanic Garden on 25 July 2019¹. The Met Office said some forecast models had produced maximum temperatures in excess of 40°C for the coming weekend and beyond, but that these figures, while they could not be ruled out, were still only a low probability¹.

NHS England's alerts stated that hot weather could increase the health risks to vulnerable patients³. Its Level 2 alert of 7 July gave a 60% probability of heat-health alert criteria being met between 0900 on Monday 11 July and 0900 on Friday 15 July in parts of England². Its Level 3 alert of 8 July gave a 90% probability of criteria being met between 9am on Monday and 9am on Friday in parts of England³.

Dr Sousa also said most people can enjoy hot weather when it arrives, but that it is important to keep yourself hydrated and to find shade where possible when UV rays are strongest, between 11am and 3pm, and that those with vulnerable family, friends and neighbours should make sure they are aware of how they can keep themselves protected¹. Government advice is that 999 services should be used in emergencies only, with advice from 111 for non-emergency health advice¹.

Why it matters for households

The alerts covered most of England, with the highest level in the southeast, and applied to the week beginning 11 July 2022, with an Amber Extreme heat warning then extended to Sunday 17 and Monday 18 July¹. The Met Office said the Amber warning highlighted likely adverse health effects for the public, not just those most vulnerable to extreme heat¹. NHS England said hot weather could increase the health risks to vulnerable patients³. The UKHSA advice quoted was to keep hydrated, find shade where UV rays are strongest between 11am and 3pm, and make sure vulnerable family, friends and neighbours know how to protect themselves¹. The heat-health alerts guide explains what the yellow, amber and red levels mean, and the UKHSA guide covers the agency's alerts and outbreak advice.

What happens next

The Met Office said an extension of the Amber warning would be considered in the coming days, and that details of temperatures for late in the following weekend and early the next week would be added as forecasts were updated¹. NHS England later issued a Level 2 alert at 9.17am on Thursday 21 July 2022, giving a 60% probability of heat-health alert criteria being met between 9am on Thursday and 9am on Monday in parts of England⁴. It issued a Level 1 summer preparedness alert at 8:49am on Monday 25 July 2022, stating that temperatures were not expected to reach heatwave threshold values until further notice⁵. Households can find sign-up details in the guide to signing up for heat-health alerts, and the heatwaves and drought hub covers wider summer risks.