Masterclass: Setting operational thresholds for Heat Early Warning Systems

Defining heatwave events and optimal public health heat alerting systems remains complex and challenging. Should they be impact-based, and what information is needed to make them so? If this information is unavailable, are climatological approaches alone effective?

This masterclass addresses these questions and provides insight to some of the practical and operational considerations that both meteorological services and public health agencies may need to take when either developing or improving existing heat health thresholds for action.

Recordings and presentations

Lecture 1. Introduction to Warning Systems

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Lecture 2. Data Considerations

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Lecture 3. Working Together

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Learning Objectives

  • To understand the reasons for setting an operational threshold
  • To understand methods for describing exposure-response relationships and population-based thresholds using epidemiological (e.g. daily mortality) and meteorological data
  • To understand how to work with NMS on indicators for warnings



Ross Thomson, Public Health England

Ross is a scientist within the Extreme Events and Health Protection team at Public Health England, since 2016. In this time Ross has developed his reputation within the arena of heat and health and has extensive experience in the operational aspects of heat health action plans and their associated early warning systems. Ross is currently working with UK Met Office colleagues on assessing the English Heat Health Warning Aystem currently in place, and so is well placed to deliver this Masterclass on setting operational thresholds for action.

Carolina Cerrudo, NMS Argentina

Carolina is a meteorologist from the University of Buenos Aires who also has many years of experience in science popularization and communication of science to different audiences. This lead her to study a social science post-degree in Public Communication of Science and Technology. Carolina is currently working at the National Meteorological Service of Argentina, in the Services and Applications area. Since 2014 she has been working on a Weekly Overlook of High Impact Weather Events report, and this experience let her work with other WMO members in the Impact-Based Forecast (IBF) and Warnings Expert Team. She is currently working on laying the foundations for future IBF implementation, in the context of the National Meteorology Services strategic plan.


Sari Kovats, London School of Hygiene and Tropical Medicine

Sari Kovats is an Associate Professor at the London School of Hygiene and Tropical Medicine in the UK. She teachings on climate change, health and sustainable development. She is a member of the International Steering Committee of GHHIN, and co-leads research on health protection responses for the NIHR Health Protection Research Unit in Environmental Change and Health at LSHTM.