NEW YORK (CBSNewYork) – Many prefer staying indoors during a heat wave, but some people are hitting the streets to serve the elderly meals while the temperatures soar.

Volunteers were out going door to door for Citymeals-on-Wheels visiting home-bound seniors and lugging heavy food bags through steaming hot walk-up apartments.

“I’m so appreciative… You have to do this thing in this hot weather. Not only to me, for everybody,” senior Zoila Chunoo told a Meals-on-Wheels worker.

“It’s been really hot today, it’s really humid,” volunteer Emily Engel Peso told CBS2’s Hazel Sanchez. “The heat I can kind of deal with. It feels like you’re in a sauna… but without any of the luxury.”

Before heading out on their routes, volunteers are reminded to stay hydrated and to report if a client shows signs of heat exhaustion or doesn’t have a way to stay cool. Doctors say many seniors aren’t able to regulate their body temperature like younger people can.

“Make a note by that senior’s name,” Meals-on-Wheels worker Vivienne O’Neill instructed. “That this senior has no air conditioning or no fan in their apartment. That’s the most important thing for today.”

New York City’s Meals-on-Wheels program delivers 18,000 meals every day, and especially when temperatures are at their worst.