When someone is having a number of symptoms it is important to consider whether they are all part of one underlying process or separate issues occurring at once. You should talk with a physician about the symptoms your father is experiencing to help further evaluate what may be causing them.
Changes in smell can be caused by a number of issues. If your father is a smoker, over time smoking can change the way a person smells and tastes the things they come in contact with. Your nose is connected directly to your brain, so some kind of neurological problem could also be the cause. If may be worth it to consult a neurologist.
Changes in temperature sensation (cold intolerance, feeling warm all the time) accompanied by changes in heart rate and blood pressure could be related to an underlying thyroid disorder. This could also cause overall weakness and sometimes, light-headedness. An endocrinologist
can help further evaluate if a problem with the thyroid is contributing.
Hunger pangs could be related to not eating frequently enough, a peptic ulcer, reflux disease or gastritis. A gastroenterologist
can help further evaluate these type of symptoms.
It is not possible to determine whether all these symptoms are related or separate without seeing a doctor
. I strongly advise you consult your physician in person for further evaluation.