Dr. Grace Lim made a startling discovery on Wednesday as she delivered her weekly health talk to the 120 elderly guests at the So Others May Eat hot lunch program.

The day was gray, and the waterlogged clouds promised yet another badly needed downpour. In one of the wettest rainy seasons in memory, the doctor’s topic was staying dry, staying warm, staying healthy.

“How many of you own an umbrella?” asked Dr. Lim.