Heat waves are a slow-onset disaster. Examine India's preparedness through Heat Action Plans.

Unlike a cyclone, a heat wave destroys no assets and leaves no visible debris; it kills quietly, over days, through cardiac, renal and respiratory stress. The Climate Impact Lab projects about 15,800 additional heat deaths in India between September 2026 and February 2027 under an exceptionally strong El Niño [1] — a scale that tests whether Heat Action Plans (HAPs) have matured from advisories into preparedness.

Why heat behaves as a slow-onset disaster

• Onset is gradual and cumulative; IMD thresholds are crossed over successive days, so damage accrues rather than strikes [2].
• Impacts are diffuse — mortality, labour productivity, power demand, water stress — and rarely attributed to heat in death records.
• 2026 illustrates compounding: a national rainfall deficit of 15% below normal links heat with agrarian and energy stress [1].

Achievements of the HAP framework

• Ahmedabad's 2013 plan, scaled through NDMA guidelines, institutionalised colour-coded alerts, hospital readiness and public advisories [2].
• Coverage has widened from a single city to numerous states and districts, with IMD–health department early-warning linkages [2].
• Financing exists: SDRF/NDRF under the Disaster Management Act, 2005, plus a discretionary window allowing states to use up to 10% of SDRF for locally notified disasters [4]; the 16th Finance Commission has recommended a ₹2,04,401 crore SDRF–SDMF corpus for 2026–31 [5].

Persisting gaps

• Of 15 state HAPs reviewed by CEEW, only two had conducted a heat risk and vulnerability assessment — plans cannot prioritise wards, occupations or age groups [3].
• Most track only peak daytime temperature, ignoring night-time heat and humidity, which prevent bodily recovery [3].
• Funding sources are usually unnamed, and outdoor workers lack enforceable rest, shade or wage protection.

HAPs have shifted India from reaction to early warning, but remain advisory-heavy and vulnerability-blind. Rewriting them around district heat-risk maps — CEEW maps 734 districts on 35 indicators [3] — tying triggers to night-time heat and humidity, and funding mitigation through the SDMF window would convert warning into protection, advancing SDG-13 and the right to life under Article 21.