Designing early warning systems for heat and MNCH

Designing early warning systems for heat and MNCH

Centuries ago, early warning systems looked very different. A lookout would climb a tower and scan the horizon, eyes straining for signs of danger. Today, our warnings arrive as quiet pings on phones. But the idea remains the same: know what’s coming — and act before it’s too late.

Studies have shown that risks for adverse maternal outcomes start rising when the daily mean temperature is above 20 ºC. But the science is clear: preterm births, complications, and stress on both mother and baby increase with heat.

That’s why building an early warning system for heat that meets the design needs of pregnant women and mothers of newborns and children matters.

A joint collaborative effort of the whole HIGH Horizons consortium have had the chance to explore this ancient idea in a thoroughly modern context. They are developing an early warning system for heat exposure tailored to pregnant and postpartum women — who are more vulnerable to rising temperatures, and whose care is too often overlooked in climate plans.

The app is called the MotherHeat Alert, and it’s part of a larger shift in how we think about climate, health, and technology.

Clara Heil, a PhD researcher on the project at Lund University, said she and her colleagues hope the app “can supplement their current and intrinsic understanding of heat of how these vulnerable groups can cool down, as well as how to redesign daily activities to avoid too much heat.”

Why early warning systems matter — now more than ever

The climate is changing faster than many health systems can adapt. Even in Sweden, where Heil conducts HIGH Horizons research, she’s seen unusually hot months — with September 2024 bringing multiple days above 25°C.

And yet, Heil says heat is not widely perceived as a danger in Sweden. People flock to the sun without realizing that what feels like a gift could be a potential danger if they are exposed for too long or at a temperature that is too high — particularly for pregnant women.

“Even in places like Sweden, we need to be aware that this is a risk that’s growing,” said Heil.

In a context such as rural Zimbabwe, the challenges are greater. Women may be expected to be out working in the fields in the heat of the day, and may struggle to access cool indoor spaces, water, and even shade.

This is where early warning systems can make a difference, whether it’s in Sweden, South Africa, Zimbabwe, or any other country in the world. Early warning systems when adapted to local context can help people in communities across the world to fully understand the weight of the risks heat poses to pregnant women and infants, and to give people time to act preventively. They’re designed to alert people, arouse awareness of heat risks, — and provide the lead time — to take action and protect themselves.

In a warming world, early warning systems may be one of our most powerful tools to protect pregnant and postpartum women and their babies from the impacts of heat exposure.

What makes a good early warning system?

Heil named four pillars to any successful system:

1. Timely detection — knowing the hazard (heat) and when a heat health risk is emerging, using context-specific thresholds and local data (like temperature or heat stress indices).
   
2. Accurate analysis — assessing the severity of the threat, including how it impacts different people in different places.
   
3. Effective communication — delivering the message in a way people understand, trust, and can act on.
   
4.  Action plan – building up heat health knowledge and response capacity, taking action to reduce heat health risks.

With MotherHeat Alert, HIGH Horizons researchers are trying to do all four — and to do it in a way that respects the daily realities of women in Sweden, Zimbabwe, and South Africa, where researchers are currently testing the app in urban and rural settings.

Designing for impact

Why an app? How will people even use it in places like rural Zimbabwe, where pregnant and postpartum women may need it most?

While acknowledging the gaps in accessibility, Heil believes that digital tools like MotherHeat Alert — when thoughtfully designed — can be surprisingly inclusive.

Smartphone use has risen sharply in places like South Africa, for instance, where apps like MotherHeat Alert can reach people directly, quickly, and at scale.

The researchers have built MotherHeat Alert not for women, but with them. That means co-designing and adapting messages to local language and context (it’s “pram” in South Africa, not “stroller”), testing recommendations and messages, and making sure the interface is easy to use. And locally adapted.

• In South Africa, Zimbabwe, and Sweden, the researchers are testing the app with over 600 pregnant and postpartum women and 60 health workers.
  
• In Zimbabwe, where access is patchier, the researchers are hoping community health workers who do have phone access to download MotherHeat Alert can make sure the messages reach rural women.
  
• In Sweden, where ethical approval for the study has just been given, the goal of promoting the app is different — less about encouraging pregnant women to take action, and more about raising public awareness before future risks grow larger.
  

Messages from the app include recommendations such as to stay hydrated, adjust clothing design and materials, and move to cooled environments.

All the messages are available in the various local languages in the areas the app serves, and are tailored for the local population. Messages in Zimbabwe and South Africa for instance contain different advice on storing water. In South Africa, the app prompts: “”Try to store water in a Jojo tank, 5-liter bottles, 20-liter containers, drums, and buckets”, while in Zimbabwe the message is “”Store water in a clay pot/chirongo or a ‘josaki‘ to keep it cool throughout the day”.

The categories of messaging are:

1. Stay hydrated
2. Adjust clothing design and materials
3. Directly cool the body
4. Plan ahead
5. Stay in cooled environments if possible
6. Avoid / Limit direct sun exposure
7. Take care of yourself
8. Utilise support structures

The future we’re building

What might success look like for MotherHeat Alert? A mother in Zimbabwe who changes her market hours to avoid the afternoon heat. A woman in Sweden who pauses before sitting in the sun at the beach — not out of fear, but awareness.