Five steps from a problem to its solution.

Help me design and build a first working prototype for this problem in Assam, India.

Problem: People in Assam aren't warned of dangerous humid heat, because India's heatwave alerts look at temperature alone.
Who it hurts: Residents of Assam's cities and districts, especially outdoor workers, children and older people, during the humid pre-monsoon and monsoon months.
The moment it hurts: A day when the thermometer stays under the heatwave threshold but humidity pushes the feels-like temperature past 50°C, and no alert is issued.
What people do today: Districts issue occasional precautionary advisories, such as school closures or revised timings. Most people rely on the official heatwave alerts, which rarely include Assam.
Why it is still unsolved: The official heatwave criteria use maximum air temperature and its departure from normal; relative humidity is not part of them, so Assam rarely qualifies and has no Heat Action Plan.
What solved looks like: A free daily heat-stress alert for each Assam district, by SMS and web, based on wet-bulb or feels-like temperature from public forecasts, with plain advice for outdoor workers and schools, checked against at least one past summer of local observations.
Where: Assam, India

First, list what you would need to learn from the people affected before building, as interview questions.
Then propose the simplest version that would help, the screens or messages it needs, and the data it would use.
Keep it cheap to run, accessible, and respectful of people's privacy. Flag anything you are unsure about instead of guessing.