Below are common feline emergencies and what you should do in case something like this occurs. You should always get your cat to the vet after any of these situations, even if not stated in the instructions below.  These should be considered "temporary" fixes to keep your cat alive while in the process of getting help.  First aid care for your cat before/on the way to getting professional help increases the chances of a positive outcome.

Hit by Car / Fall from Height
You need to move your cat out of any dangerous area, using a towel or coat as a stretcher.  Put him in a large box or pet carrier to transport him to the vet.  Cats falling out of high windows is called "high-rise syndrome" and is all too common - make sure you have secure screens on all of your windows to prevent this.

Drowning
If your cat accidentally falls into a pool or other body of water, check to see if it is responding.  If not, hold it upside down, firmly grasping the back legs, and vigorously swing the cat downward to remove water from the lungs.  If he is still not breathing, perform CPR.

Choking
If your cat is choking (gasping for air or pawing at its mouth), attempt to find the object with a flashlight and remove it with tweezers or a spoon handle.

Burns
Clean burns gently with soap and water and then apply a cold compress for 30 minutes.  Cover the burn with a loose bandage and take it to the veterinarian.  Do not apply ice or ointment directly to the area.

Electric Shock
Most common in kittens.  If the cord is still in his mouth, unplug it.  If that is not possible, use a wooden broom handle to remove the cat away from the live wire.  Cats often go into cardiac arrest - perform CPR if necessary. Take the cat to the vet immediately. There may be burns around the mouth and pulmonary edema (fluid accumulation in the lungs) often develops.

Frostbite
Paws, tails, and ears are the most common areas affected, and the skin will appear pale at first (it becomes red, hot, painful and swollen later).  Warm the frostbitten area rapidly by immersing it in warm water for 15 minutes.  Cover the area with a loose bandage, being careful not to rub the skin, and get to your veterinarian immediately.

Hypothermia
Caused by exposure to cold weather, hypothermia can cause a very slow pulse and breathing rate, seizures, coma, and death.  Give the cat a warm bath, taking a rectal temperature every 10 minutes.  When the cat reaches 101 degrees Fahrenheit, remove from bath and wrap the cat in blankets/towels slightly warmed in dryer.

Heatstroke
Cats with heatstroke will pant, have bright red gums, and could collapse.  Rectal temperature can hit 110 degrees Fahrenheit.  Wrap the cat in towels soaked in cool (not cold) water to lower its body temperature, monitoring body temperature every 10 minutes.  Stop cooling when the temperature reaches 103 degrees Fahrenheit. 

Seizure
Common causes of seizures include heatstroke, low blood sugar, brain tumors, liver disease, and epilepsy. If your cat has a seizure, make sure to clear the area so the cat does not hit anything during the seizure.  Don't try to hold the cat's mouth open - obstruction of the airway by the tongue is not common, and this could result in an accidental, serious bite.  Cats do not have control of their actions when having a seizure and could accidentally clamp down and not let go.  Provide gentle restraint during the seizure by holding a light blanket or towel over the cat.  Afterwards, confine the cat and monitor its breathing and pulse.  Call your veterinarian and schedule an appointment, notifying them of what happened.