Halacha Yomi: April 23 2018

If one will need to remove their yarmulke in order to make a livelihood, and cannot wear something else such as a cap or toupee on his head, for example it will be to hot and disturb his working, it is permitted to go without a head covering (one must be honest with himself before making this decision). However, this person must wear a yarmulke when going into another room or outside, and while reciting a bracha.