Syndromic surveillance summary: 24 May 2026 week 21
Updated 28 May 2026
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Reporting week 21: 18 to 24 May 2026
During week 21 there were increases observed in ‘impact of heat’ syndromic indicators across NHS 111, emergency department (ED), ambulance and GP out-of-hours systems. These increases were in line with an amber heat health alert in place across parts of England. There were also increases in other indicators linked to the extreme heat, including NHS 111 calls and online contacts and GP out-of-hours contacts for insect bites.
Remote health advice syndromic surveillance system
During week 21, there was a sharp increase in NHS 111 triaged calls and online assessments for ‘heat exposure or sunburn’ over the bank holiday weekend 23 to 25 May. Increases were noted across all age groups and regions. These increases were in line with an amber heat health alert in place across parts of England. Calls and online assessments for insect bites also increased and were above levels usually observed at this time of year.
Please note that due to a technical issue the NHS 111 online vomiting indicator has been temporarily removed from this bulletin.
Access the remote health advice syndromic surveillance bulletins
GP in-hours syndromic surveillance system
During week 21, the consultation rate for allergic rhinitis decreased overall and was below seasonally expected levels. There was a slight increase in upper respiratory tract infections, which remained above expected levels, however, all other GP in-hours respiratory infection indicators were decreasing or stable.
Access the GP in-hours syndromic surveillance bulletins
GP out-of-hours syndromic surveillance system
During week 21 there was a sharp increase in GP out-of-hours daily contacts for ‘heat or sunstroke’ with activity above seasonally expected levels. The increases were in line with an amber heat health alert in place across parts of England. Contacts for insect bites also increased, particularly during the holiday weekend, and were also above expected levels.
Access the GP out-of-hours syndromic surveillance bulletins
Emergency department syndromic surveillance system
During week 21, ED attendances for ‘heat or sunstroke’ increased sharply towards the end of the week and were above seasonally expected levels. Increases were particularly noted in London and the South East and were in line with an amber heat health alert in place across parts of England.
Access the emergency department syndromic surveillance bulletins
Ambulance syndromic surveillance system
During week 21, there was a sharp increase in daily ambulance calls for ‘impact of heat or cold’ in line with an amber heat health alert in place across parts of England. Calls for ‘unconscious or passing out’, ‘collapsed with unknown problem’, allergic reactions and injuries also increased in line with the heat alert, all of which were above seasonally expected levels during week 21.