Hyperthermia is becoming too hot (dehydrating - heatstroke)
You need to decrease the pet’s temperature as soon as possible. Wrap a wet towel around the pet and put them in a cool room, if you can, place a fan nearby but ensure that they do not get too cold.
You can massage the pet’s legs vigorously to help them maintain the blood flow and give them plenty of cold water to drink.
Hypothermia (extreme cold)
If your pet has become cold due to them being wet, the first thing you must do is dry them with a towel quickly. Wrap many thin layers around the pet so they can warm up, many thin layers is better than one thick layer as it holds the heat more effectively (better insulation).
If you have a hairdryer at hand, use it to warm up your pet but don’t get too close to it. If you notice your pet becoming distressed, stop .