I have what looks like a heat rash covering belly chest and back, is this heat rash or could it be something else? All the red bumps are raised

See below. Heat Rash(Miliaria) occurs from blockage of sweat glands. Excessive sweating leads to overhydration of the outer layer of the skin, which is composed of dead cells. The excess accumulation of dead cells blocks the sweat glands and cause sweat to accumulate under the skin. This causes small papules(bumps) and vesicles(tiny blisters) to appear appear. SEE:..http://bit.ly/1CW6vnd.