Wearing New Caps in the Nine Days

Question

I am the director of a summer camp for yeshuiva bachurim. We ordered caps for the boys to protect them from the sun when they are involved in outdoor sports, but their delivery got delayed and they are only arriving on the 2nd of Av. Can we give these new caps to the boys to wear during the nine days or is this a problem of wearing a new garment?

Rav Auerbach 

It is prohibited to wear a new garment during the Nine Days (see Shulchan Aruch 551,6). If it is a new garment that one recites the beracha of Shechiyanu on, one should not wear this even during the three weeks (ibid. Mishna Berurah 45).

However, these hats are being worn primarily to protect them from the sun, and do not have the chashivus of a new garment. Therefore, they are not included in the prohibition not to wear a new garment during the Nine days.

If I may add, the halacha directs us to be m’meyat b’simcha during the Nine Days (Shulchan Aruch 551,1). One must make a special effort not to forget the spirit of this time, which is to be focused on the mourning of the Beis Hamikdash. As the director of the camp, you should make sure that the activities that the boys are involved with during the Nine days do not cause them to be mesiach daas from the avelous.