Hurricane-prone New Orleans is lacking trees. They could help with rising heat.

The volunteers fanned out across New Orleans while the sun beat down and the temperature kept rising.

Sensors attached to their cars captured the stifling heat on a July afternoon, transmitting data back to the group's home base in Hollygrove-Dixon.

There, Raymond Sweet served as a lieutenant of sorts. He fielded calls every few minutes as drivers asked where next to go. His table was strewn with printouts of routes and he flipped between a barrage of incoming texts and a sheet of names.

The temperature had reached 98 degrees. A wet bulb thermometer rested on a tripod out back, measuring how humidity was making the heat worse. It clocked 83.5 degrees — dangerously high and becoming unsafe for people to spend time outside.

The brutally hot day was perfect for their experiment.

Sweet