Tony Williams, 86, stumbled while spraying weedkiller in his garden during a June heatwave, breaking several ribs.
His wife Faith, 87, came rushing to help, but also fell in the garden in Welsh St Donats, south Wales.
Daughter Ruth, unable to contact her parents, alerted a neighbour who found them lying metres from each other, Tony with a cushion beneath his head, his wife by his side.
"It's a very, very sad set of circumstances and all so unnecessary -- just because dad was determined to try to spray some rather inaccessible weeds while it was dry weather," she said.