One of the reasons overweight people aren't so crazy about exercising is that their added padding helps raise body temperature making them hot, sweaty and tired. A new report suggests that holding something cool - even a cold water bottle will do - can help keep internal temperature from rising, allowing for a longer, more comfortable workout. To study this interesting phenomenon, Stanford University researchers equipped half of a group of 24 obese women between the ages of 30 and 45 with handheld cooling devices containing water at 60.8 degrees Fahrenheit. The other half of the group received the same devices filled with water at 98.6 degrees Fahrenheit. The goal was to increase the exercise duration of both groups to 45 minutes at 80 percent of their maximum heart rates. Those in the control group dropped out early, but those using the cooling devices continued to work out for the study's three-month duration and cut an average of five minutes off the time it took to walk 1.5 miles, decreased their waist sizes by three inches, lowered their resting blood pressure and raised their exercise heart rate.