My father had a slight fever last evening i.e. 99.4, I gave a paracetamol as precaution and the fever went off. Since then the body temp is around 97, the O2 level is also around 98-99, no other issues. He takes medication for BP. He is 60 years and do yoga and exercise as well. Today he said that he is feeling a bit weakness and not fresh enough that he should feel. Please suggest any medication or diet. We are currently in a village of Bihar, the weather is hot during day and it changes drastically at night and becomes cold.