From our library:
SYMPTOMS/SIGNS OF DANGER OF HEAT STROKE:
1) Rabbit is laying stretched out
2) Panting or heavy breathing
3) Sometimes there's foaming at the mouth
4) Muzzle is wet
Tips for prevention of Heat Stroke:
Heatstroke can kill a rabbit very quickly. Some things that you can do to prevent such an untimely and unnecessary death for your lagamorph are listed below.
1) Be sure to provide your rabbit shade. Rabbits can get sun/heat stroke just by having their cage in the sun. Best to be sure the location of the cage is away from where the sun rays will beam in.
2) Don't subject your rabbit to extreme temperatures: hot or air conditioning. Air conditioning can be used, but it's best to have your rabbit in a separate room so that the room doesn't get too cold or the air isn't blowing on the rabbit.
3) Be sure they have a lot of water; they tend to drink more in the summer to stay cool.
4) You can use a fan. I like toaimthe fanso that the air will reach part of the cage, but if the rabbit feels it's too much,s/he can move out of the way. If you're going to keep your fan on all day, best to keep it on low.
5) If the rabbit is indoors, on really hot days Iclose the shades to keep out as muchheat as possible.
6) If the rabbit is outside, you may want to mist the ears a bit in the heat of the afternoon.
7) Some people fill old milk cartons or soda bottles with cold water and put them in the cage with their rabbit so that s/he can lean up against it if it gets very hot.
WHAT SHOULD YOU DO?
1) Get the rabbit to a cool area. Get a fan, and put it on him/her with a speed of medium or low.
2) You can dip your rabbit in a Lukewarm bath if it is almost lifeless. Dip up to the ears. Never immerse the rabbit completely in the water. You have to work on bringing its temperature down slowly. Putting it in a cold bath or directly applying ice to it's ears is not recommended or good for the rabbit. That could lead into other problems of stress and shock to its system and you could lose the rabbit that way.
3) Put a cold washcloth on the rabbit's ears. You could wrap ice cubes in a washcloth and apply to the inside and outside of the ears. The blood from the rest of the body will circulate into the rabbit's system once cooled.
4)Keep him/her hydrated, even if you have to put some water in a syringe to give orally to keep the fluids in his system up. The rabbit may have to get an intravenous tube.
5) Try to keep calm so that the rabbit doesn't get stressed.
6) Put an old milk carton or soda bottle in the cage filled with cold water so that the rabbit can lean up against it.
Here is the link:
http://www.rabbitsonline.net/view_topic.php?id=27899&forum_id=10