It sounds like to me you are just thirsty. A lot of times, people confuse their hunger mechanism for thirst. Since traditionally a lot of our fluid consumption came from food and not directly drinking water, your body can make you feel very hungry when you're actually very thirsty. Drink more water and salt your food - if the hunger is due to the heat wave, simply adding more fluid and electrolytes could fix it. Also, consider shifting some calories away from fats and to carbs, particularly fruits. That'll make you retain more water, which could be what your body needs.
Don't put your trust in anyone on this forum, including me. You are the key to your own success.