Not necessarily. I am a nurse and was working in the ER during and after Katrina. My state was one of the hardest hit. People can and do die from heat exposure. The elderly, very young, and chronically sick are all at risk. Unfortunately, lack of water and excessive heat did cause heat stroke in some elderly people in my area. We had no air conditioning in our hospital for weeks and our ER was not well ventilated with outside air. I saw several young, healthy nurses suffer heat exhaustion during this very difficult time.
My point is that heat and cold are both dangerous. I think that those from the south who have been though our share of these terrible storms are trying to be as supportive as we can. Unfortunately, the power takes time to come back on and it is frustrating. My in laws had no power for 2 months so I know how frustrating it can be. We were 3 weeks. And on a personal level, my sister was in New Orleans during Katrina, lost everything, moved to Hoboken to work in NYC, has no power, a flooded apartment, a flooded car, and is 36 weeks pregnant. So trust me, I am sympathetic.
My advice for people without power is to go to a shelter, friends, or family if possible (I know car travel is tough with the gas shortage, and I really understand this one). If you can't go somewhere with utilities, try to stay in the warmest room possible with all family members, lots of blankets, and stay close together for body heat. I am keeping all those affected in my prayers and hoping that power is restored ASAP. Stay safe everyone.