As for living in a very hot district,

Q: A person abstained from fasting when he was 28 until he became 35 years old. He then turned to Allah (Exalted be He) in repentance and now is confused as to whether he should make up for these months which he missed, pay Fidyah (ransom), or give Sadaqah (voluntary charity)? Please advise us, may Allah reward you with the best.

(Part No. 10; Page No. 351)  A: In the case where he was praying when he did not fast, he has to make up for these days and feed needy people for each day that he did not fast. He should give them half a Sa` (1 Sa`=3 kg. Approx.) of wheat or rice. However, if he was not praying, Tawbah (repentance to Allah) will suffice him and he does not have to make up for the days that he did not fast or to make up for Salah. This is because abandoning Salah is a major sin and Riddah (apostasy), and an apostate is not required to make up for his actions.May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.