RABBITS CAN STILL ENJOY A GOOD RUN EVEN ON COLD DAYS WHEN THERES SNOW 

I have found a fantastic way of protecting the rabbits here from the summer heat. Its an aluiminum greenhouse shading.
The company that provided it has given it to us for free and i thank them very much. This material has the potential to help your pet rabbits as well. The one i have cuts out up to 60% of the heat and glare getting to the rabbits in there cages. Its in meter lenthgs and ive just attatched it to batons of wood in sections so it can be stored away easily in the winter, this is atatched to a simple frame. I carnt beleive the difference it has made. I can now stop worring about the hot weather. The details and links to the simplecontrol people who supply it are as follows.
link to web site:

ALTHOUGH IVE JUST DRAPED IT OVER THIS RUN IT COULD BE DONE MUCH BETTER,The summer is just around the corner. Rabbits in the wild live underground and are not out in the heat of the day.
Protection is vital against the heat of the sun, many rabbits every year are dying from heat stroke. Hear are a few helpfull hints on
protecting your rabbits.
Heatstroke most commonly occurs when temperatures are 82° or above. High humidity (over 70%) can also increase the likelihood of heatstroke. Other risk factors include inadequate shade and ventilation, overcrowding, and other forms of stress.The signs of heat stroke are as follows.
Fast, shallow breathing
Hot ears
Listlessness
Wetness around the nose area
Tossing back of head while breathing rapidly from open mouth. 
Ultimately, death
What to do, remove your rabbit from the hot area and contact your vet
wet ears feet and fur with cool water. Do not put the rabbit in water as cooling them down to quickly can cause life threating problems.
Your vet will lower your pet's body temperature to a safe range (if you have not already) and continually monitor his temperature. Your pet will be given fluids, and possibly oxygen. He will be monitored for shock, respiratory distress, kidney failure, heart abnormalities, and other complications, and treated accordingly. Blood samples may be taken before and during the treatment. The clotting time of the blood may be monitored, since clotting problems are a common complication.
things to keep your rabbit cool are, tiles layed in their cage to lay on , ice cubes in their water bottles, misting of their ears.fans , air conditioners, umbrellas over the cage.
Place the cage in as much shade as possable, if the cage is in a shed then ventilation is vital.
I am testing out a sun screen to keep my rabbits cool. Its a aliuminum grrenhouse shading that sould reflect up to half the heat away from my cages. Will let you know later how good it is.