If your wife is pregnant for the first time it is natural for the early pregnancy
symptoms to be exaggerated. The heat is due to the raised body metabolic rate due to the pregnancy. Please see that she takes sufficient rest and see that her surroundings are cool and comfortable. Give her plenty of fruits and fruit juices; dry fruits would be tolerated better. This state may continue for a month or two. It is good to see your concern. Please take her for regular follow up and take your consultant's advice. Wish you good luck.