Physical stress resulting in depletion of oxygen to the heart. Lawn mowers normal overdo for which their heart is not physically capable. Hence acute massive Infarction results and sudden death/death ensues. People in the above age group must be warned not to overdo specially in hot (water depletion) or cold weather (coronary spasm). Precautionary method is to take a sublingual pill prior starting mowing but within limits say 5 minutes than a break than 10 minutes and a break, better on empty stomach, nothing doing after you had your breakfast or a large meal.