A heatmap displays average life expectancy for selected countries across seven decades, from 1960 to 2020. Each row represents a country, with colored cells encoding age values using a blue-green gradient where higher life expectancies appear brighter. The visualization uses p5.js, loading CSV data via `loadTable` and mapping numeric values to fill colors through the `color()` function. Country labels and a legend with age ranges are rendered alongside the grid, with axis annotations for years and life expectancy values.