Which property of water explains its ability to prevent sudden changes in body temperature?

(High) Heat Capacity

Heat capacity is the amount of heat needed to raise the temperature of a substance by 1 unit degree (Celsius, Kelvin, Fahrenheit, Rankine). 

Water has a relatively high heat capacity, which means that it would have to absorb relatively large amounts of heat before it could actually have a large change (i.e. increases) in temperature. Conversely, it would have to give off a lot of heat in order for it to cool down.

The heat capacity of 1 gram of water is 4.184 Joules/°C, which means that 1 gram of water needs 4.184 Joules of heat to increase its temperature by 1°C. In comparison, 1 gram of copper only needs 0.385 Joules to raise its temperature by 1°C, which means that copper heats up by about 10 times more than water when subjected to the same amount of heat. 

Writing, you can revisit previous parts of the lesson by returning to the course map. be sure to refer to the lab’s student guide, which you can find on the first page of the lab experiment activity