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Community climate resilience

Warning carers before the weather turns dangerous.

Chaleur is a mobile application, currently in development, that alerts carers when heat, air quality, UV or thunderstorm asthma turn dangerous for someone they care for, so they can act while it still helps.

In development Working prototype Privacy-first by design Seeking a clinical partner

The idea

Isolation is among the deadliest risk factors in a heatwave, and one of the few you can change.

Extreme heat kills more people in Australia than bushfires, floods and storms combined, and during Sydney's 2011 heatwave deaths rose by around 13 per cent, with people over 75 worst affected. Research into who dies in these events, including a meta-analysis of heat-wave mortality, consistently finds that those most at risk are people who are isolated or rarely leave home, and that social contact during dangerous conditions is one of the few protective factors a community can actually influence.

Chaleur is built on that finding. It watches the environmental hazards relevant to that population and, when official guidance directs an at-risk person to act, prompts the carer who already cares for them to make the call, share the advice, or arrange a check-in while there is still time for it to matter.

What Chaleur does

Four hazards, one prompt to the person already paying attention.

The carer is the hero and the application is the support. Chaleur reads conditions from official sources and translates them into a clear, timely prompt, leaving every judgement about a particular person to the person who knows them.

Extreme heat

Tracks official heat warnings and flags the days when staying cool stops being routine and starts being urgent.

Poor air quality

Watches smoke and air-quality categories from state environment agencies, named exactly as the source reports them.

Extreme UV

Surfaces the sun-protection window when ultraviolet levels reach the point at which official advice says to act.

Thunderstorm asthma

Relays epidemic thunderstorm-asthma warnings in the places and seasons where authorities issue them.

Chaleur has climate intelligence rather than personal intelligence. It knows when conditions are dangerous, and it never claims to know when a person needs care. That judgement stays with the carer.

Privacy by design

Privacy is the first decision, not a policy added at the end.

Chaleur is being designed to handle the most sensitive information (who a person cares for, and why they are vulnerable) without that information ever leaving the device it was entered on. The architecture treats a bespoke privacy mistake as fatal to the project, so the boundaries are built in rather than promised.

  • Sensitive data stays on the device. Health details and contacts are held locally and are designed never to sit on a server.
  • Coordination shares almost nothing. When co-carers coordinate, only a thin, non-personal signal passes between them, never a person's identity or condition.
  • Independent review before any real use. Encryption, key management and data-protection design are slated for external expert review as release gates, not self-certified.

Where Chaleur is

A working prototype, and an honest account of what it is not yet.

Built and working

  • Account setup and on-device profiles for the people a carer looks after
  • Live hazard alerts with plain-language, source-attributed guidance
  • A community circle for the people who share the care
  • Co-carer coordination, so help is not duplicated or dropped
  • A clearly labelled demonstration mode for showing the alert experience on a calm day

Not claimed yet

  • Chaleur is not publicly available to download
  • Nothing in it is clinically validated; its guidance is provisional and drawn from official public-health sources, pending expert sign-off
  • It carries no clinical, council or government endorsement
  • Clinical, security and privacy reviews are planned gates before any real-world use

Stating the limits plainly is the point. A climate-and-health tool earns trust by being accurate about its own status, and Chaleur is built to that standard from the first screen.

Partner with us

Chaleur is being built as a grant-funded public good, not a commercial product.

The intended path to people is institutional distribution through a clinical partner, councils, or primary health networks, rather than an app-store launch. To take the next step, two things are needed.

A research-active clinical partner

Someone who can validate the health guidance, co-design a pilot, and anchor the project's clinical credibility.

Grant funding for a pilot

Support for a council or state-level pilot, including the equity framing and the question of where the running cost lives after the grant.

If that is you, or you know the person it should be, get in touch.

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Who is building this

Natasha Roumanoff
Founder, Chaleur · Sydney, New South Wales

Chaleur is being designed and built by Natasha Roumanoff, who is leading the product, the privacy architecture, and the clinical-partnership work.

The current prototype was built single-handedly using a modern, AI-assisted development workflow, which is what has made it possible to reach a working product at this stage as a solo, pre-funded effort. Grant funding would bring professional engineering and independent security, cryptography and clinical review to harden that prototype before it is ever placed in front of a real, vulnerable person.

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