During both the summer and winter seasons, UKHSA and the Met Office monitor weather forecasts to help health and social care professionals, emergency workers, the voluntary sector and the public cope with bad weather. When periods of particularly hot or cold weather are identified, they carry out a joint dynamic risk assessment and issue warnings if necessary.
Not just the temperature
The UKHSAs Weather Health Warnings (WHA) system changed in June 2023. While the previous system triggered alerts when a specific temperature was reached, the new WHAs use temperature thresholds in addition to other criteria including the duration of the event, the number of regions affected and the likelihood of escalation.
In addition to temperature, there are other risks such as drought, air pollution, forest fires or floods that can worsen health consequences. This change in approach is due to evidence of the relationship between temperatures and mortality; the perceived impact on the health and social care system during heatwaves over the past decade; and long term weather trends from every region of England.
How do weather and health alerts differ from weather alerts?
UKHSA works with the Met Office to decide when to activate our WHAs, but these alerts are separate from the Met Office’s own UK alerts. National Severe Weather Warning Service (NSWWS). Weather health warnings cover health impacts that may be observed due to the weather and are primarily aimed at the health and social care sector and emergency responders, while the NSWWS has a wider audience. The WHAs are divided into 2 main types:
Cold health warnings
There are currently no cold temperature specific warnings issued as part of the National Severe Weather Warning Service. The Met Office is instead issuing warnings for a range of severe weather conditions, including rain, fog, wind, thunderstorms, snow and ice. These warnings provide a holistic view of the weather and its potential impacts over a warning period that the public and emergency planners may find useful.
UKHSA explicitly considers cold temperatures in relation to weather and health warnings, among other factors (described in the WHA user manual) as part of a dynamic risk assessment carried out with the Met Office. This is due to the observed effects in the health and social care system during periods of cold weather.
UKHSA and the Met Office maintain regular contact throughout the winter season, ensuring the earliest possible issuance of UKHSA’s Cold-Health Alerts (CHAs) and the maximum possible warning time. Warnings issued by the Met Office during this period will contribute to the issuance of the level warning.
Heat Health Warnings
In England there are two early warning systems relating to high temperatures: Heat-Health Alerts (HHA) and Extreme Heat Alerts (EH). The latter are part of the National Severe Weather Warning Service. A key difference between the systems is that UKHSA’s warning system starts at the yellow level, while the Met Office’s National Severe Weather Warning Service only issues orange and red warnings.
UKHSA’s yellow alerts target those who are particularly vulnerable, such as the elderly and those with certain long-term health conditions. Action is likely to be needed at this level, particularly in the areas of health and social care. It is for this reason that orange HHAs issued by UKHSA have lower thresholds than the Met Office’s orange NSWWS warnings, meaning they are not always issued in parallel.
Due to the generally higher temperatures in London, a slightly different measurement is used to activate HHAs in the London region.
Specific to the region
Warnings from the National Severe Weather Warning Service cover the whole of the United Kingdom, while Weather Health Alerts only cover England. WHAs are issued per government region and the new automated alert system allows users to specify which area they would like to be notified about.
You can Sign up for the new warning system here or visit the devotee WHA Service web platform to view the current alert status across England. We will also share any weather health alerts on social media platforms including Facebook And X. These warnings will help our healthcare workers and emergency responders deal with increasingly extreme weather conditions, both in summer and winter.
Reference By: ukhsa.blog.gov.uk
