Minors: children under 13 and girls under 12 are completely exempt from this fast.
Pregnant women are exempt from this fast.
Nursing women, in many Sephardic communities the tradition is that after giving birth, women are exempt from fasting for 24 months, even when they are no longer breastfeeding their baby. In other Sephardic communities, and in most Ashkenazi communities, a woman is excused from fasting for 24 months only if she is still nursing her baby.
A person who feels sick, with symptoms of flu or fever, or a person with a chronic illness, such as diabetes, should not fast.
Elders should consult with their doctors to determine if fasting would affect their health. In which case they are exempt from fasting.
In addition, extreme your caution and try to keep yourself indoors protected from heat. In case of any sign of dehydration, nausea, vomits, very dry mouth, etc. DO NOT HESITATE TO BREAK THE FAST.