As soon as the death occurs it will see fast change in temperature because homeostasis had ceased and heat is lost via convection and radiation.
The temperature of the body keeps falling after the heart stops at a rate of 1.5 degrees every hour until it reaches the room temperature.
Step-by-step explanation:
By measuring the core temperature of the body, time of death can be predicted. As soon as the heart stops working the body becomes colder, this is called algor mortis. The body becomes cold as the homeostasis ceases. The temperature of body keeps falling at the rate of 1.5 degrees every and cell organelles start deteriorating, they release calcium into the muscle cells, which make them stiff. The algor mortis peaks at 12 hours and dissipates after 48 hours.
As soon as the heart stops, the temperature of the body goes down fast as it ceases to undergo homeostasis.