For some Moms, the heat may be enough appetite suppressant already. After all, we tend to get too lazy to eat and digest all that food (except maybe ice cream). Plus, it's just so hard to keep moving in this intense heat.
One other possible plus of this heat is that we'd be driven to really drink and drink lots of fluids, which is very important when trying to lose weight. We're also more likely to consume fruits, for their water and sugar content, to refresh ourselves. Again, very good for losing weight, and more timely too since there are so many fruits in season during summer.