Most diet pills have ingredients that are diueretic to supposedly help flush toxins out of the body. There is nothing wrong with that expecially if the brand you use has been clinically tested to be safe and you follow the dosage.
Unfortunately, diuretics in this summer heat may cost you more than your body's toxins. It may actually cost you your health.
Normally, you'd need at least twice the recommended amount of water when it's really, really hot because your body burns and you perspire.
You also need about that amount of water if you're on diet pills, to make up for all the water you will flush out.
But who drinks thrice the amount of recommended water intake anyway? And if you don't, you may be compromising your body by becoming more at risk of heat stroke, at least.
So do consult your physician and nutritionist before continuing to pop those pills. You may need extra vitamins as well. Remember, keeping healthy is not just about losing weight.