This is from religionclause.blogspot.com which you can find here:
“In Singh v. Carter, (D DC, March 3, 2016), the D.C. federal district court, invoking RFRA, granted a preliminary injunction protecting religious rights of an Army officer. The Army had ordered a decorated Sikh Army captain to undergo costly specialized testing with his helmet and protective mask to assure that his religiously required head covering, beard and uncut hair will not interfere with the functions of the helmet and mask. The court said:
At first blush, the challenged order appears to reflect a reasonably thorough and even benevolent decision by the Army to fulfill its duty of protecting the health and safety of this particular Sikh officer.
Yet, that is far from the complete picture. Thousands of other soldiers are permitted to wear long hair and beards for medical or other reasons, without being subjected to such specialized and costly expert testing of their helmets and gas masks. Moreover, other Sikh soldiers have been permitted to maintain their articles of faith without such specialized testing.
See prior related posting.”
You can learn more about this issue here.