Shalom HaRav, Is it appropriate for one who has a difficult time working while he fasts to take a sick leave from work - specifically, if he would be paid for a full day? It seem to be, in a sense, a sort of self inflicted sickness, so why should someone else pay for it? Thank you

ב"ה Shalom On the one hand, even in the case of self-inflicted illness, such as somebody was out in the cold without being dressed accordingly and became sick, he would be still be entitled to a sick day since he is actually not well regardless of the reasons. In this case, however, it is not self-inflicted since we are commanded by Halacha to do so. So, if one began fasting and feelsl ill, and not just feelings of discomfort which come with every fast, it wouldn't be different from a person who came down with the flu in the middle of the work day. On the other hand, we do find in the poskim, a leniency to redeem fasting by giving Tzedaka. If for example someone dropped his tefillin in a manner which requires him to fast , we say that in our times weakness is prevalent and the fast can be redeemed by giving Tzedaka instead.(See ילקוט יוסף קצוש"ע אורח חיים סימן מד). However, I have not seen this rule applied in the case of a Ta'anit Tzibbur. Then there are the halachot of one who does not feel well on a fast day, especially on Ta'anit Esther.(שו"ע תרצ"ו) There are also the halachot which apply to women, who are pregnant or nursing, which in each case a Rav should be consulted. So if you began to fast while you were working, and then became not well and again not just feelings of discomfort which come with every fast which can be slept off, then you would be considered under duress and would be allowed to break your fast. But of course, a person should do not work of exertion when he knows in advance he would be forced to break his fast. Fast well and Purim same'ach