Summer Heat
If this is your first bunny and you are keeping him outside, make sure you are prepared for the heat of summer when you set your bunny up. Rabbits have a tough time keeping cool in the summer and it's very important that you keep them out of direct sunlight at this time. Heat can be the most deadly thing your bunny will ever face.
Make sure your rabbit's hutch is out of the direct sunlight. Also, make sure that the bunny has a place to retreat that is cool and dry.
If you notice that your rabbit seems very listless, this may be a sign of heat issues. Make sure you take the bunny into a cool environment and wipe the ears down with a cool compress. Rabbit hydrate through their ears and dwarf rabbits have very small ears which can make them very prone to summer heat difficulties.
In short, help your rabbit fight the summer heat by keeping them out of it and cool as much as possible. Most people are more afraid of the cold of winter but rabbits are actually more suited to this type of climate. So make sure to give your rabbit the best possible environment to stay cool and safe in summer.