The reaction of an acid with a base, for example, results in the creation of a salt and water. Some, but not all, reactions can be reversed. See nuclear reaction. An action that results directly from or counteracts another action, especially the change in a body's motion as a result of a force applied to it.
Snakes are cold-blooded creatures, just like amphibians. When a certain animal is cold-blooded, it basically means that they are able to adapt their own internal temperature to that of their environment. When a snake is in a cool environment, their body temperature tends to drop rather quickly.
Though they are found all over the world, snakes do not, however, like the cold. This is because they are cold blooded or ectothermic. This means that they don't have the means to regulate their body temperature like warm blooded creatures.