To keep your rabbits cool during the summer heat, you can take the following measures:

1. Provide shade: Ensure that the rabbits' housing or enclosure is situated in a shaded area. Use structures, such as umbrellas, tarps, or natural shading from trees or buildings, to create shade.

2. Proper ventilation: Ensure good air circulation in the rabbits' living space. This can be achieved through well-ventilated hutches or cages, fans, or open windows.

3. Adequate water supply: Make sure your rabbits have access to fresh and cool water at all times. Consider using water bottles or bowls that can be easily replenished and kept clean.

4. Wet towels or frozen water bottles: Place damp towels or frozen water bottles in the rabbits' living area. Rabbits can lie against them to cool down. Replace the towels or bottles as needed.

5. Cooling mats or tiles: Provide cooling mats or tiles for the rabbits to lie on. These mats can be chilled in the refrigerator or freezer before use.

6. Frozen treats: Offer frozen fruits or vegetables, such as chunks of frozen watermelon or cucumber, as a refreshing treat for rabbits.

7. Limit exercise during peak heat: Avoid handling or moving the rabbits excessively during the hottest parts of the day when temperatures are at their peak.

8. Monitor temperature: Use a thermometer to regularly check the temperature inside the rabbits' living space. If it becomes excessively hot, consider additional cooling methods such as misting systems or air conditioning.

Remember, rabbits are sensitive to heat and can suffer from heat stress or heat stroke, which can be life-threatening. It's crucial to monitor them closely and take appropriate actions to keep them cool and comfortable during hot weather.