Good for your son!
I'm not 100% sure they are actually honeybees. And, if they are, they certainly aren't babies. Worker honeybees spend the earlier part of their lives inside the hive as nurse bees. These bees nurture and feed bee larvae. They also take on the job of keeping the inside of the hive clean, feeding the queen, processing incoming nectar into honey for storage, and capping the honeycomb where the honey is stored with beeswax.
It is only when they get older that the worker bees will leave the hive to collect the necessary resources from which the colony survives, such as nectar, pollen, and propolis (a a resin gathered from tree buds, sap flows, or other botanical sources. Propolis is used to seal small holes in the hive). They have a dangerous and tiring job, but work from the time the sun is up until sunset.
Maybe the bees your son is finding are these older worker bees that have suffered from heat exhaustion due to the very high temperatures this year. My bigger worry would be that they may be suffering from insecticide poisoning that farmers may have been spraying on their crops (or even gardeners have been spraying). If this were the case, I would be concerned about trying to rescue them and getting them flying again. The danger then is they could actually bring back the poison to the hive.
At the height of the summer a typical honeybee colony (hive) can have as many as 80,000 or more worker bees. The queen bee in the hive lays as many as 2,000 eggs each day (that is literally her only function). The loss of a few dozen, or even several hundred, worker bees would be insignificant to the colony. Indeed, there are probably many, many, more than this dying from natural causes every day. Worker bees literally do work themselves to death.