the moment of death:

• the heart stops.
• the skin gets tight and ashen in color.
• all the muscles relax.
• the bladder and bowels empty.
• the body temperature begins to drop 1 1/2 degrees Fahrenheit per hour.

after 30 minutes:

• the skin gets purple and waxy.
• the lips, fingernails, and toenails fade to a pale color.
• blood pools at the bottom of the body.
• the hands and feet turn blue.
• the eyes sink into the skull.

after 4 hours:

• rigor mortis has set in.
• the purpling of the skin and the pooling of the blood continue.
• rigor continues to tighten muscles for another 24 hours or so.

after 12 hours:

• the body is in full rigor mortis.

after 24 hours:

• the body is now the temperature of the surrounding environment.
• in males, the semen dies.
• the head and neck are now a greenish-blue color.
• the greenish-blue color spreads to the rest of the body.
• there is a pervasive smell of rotting meat.

after 3 days:

• the gas in the body tissues forms large blisters on the skin.
• the whole body begins to bloat and swell grotesquely.
• fluids leak from the mouth, nose, vagina, and rectum.

after 3 weeks:

• the skin, hair, and nails are so loose they can easily be pulled off the corpse.
• the skin bursts open on many places on the body.
• decomposition will continue until the body is nothing but skelital remains, a process that can take a month or so in hot climates, and two months or more in cold climates.