They may get down to 40 degrees. Some sunscreen and Chap Stick will help protect you from the elements. Our days may only get 75 degrees but with the high elevation you will have a tendency to burn easier. Insect repellant is wise as mosquitoes and horse flies may get bad. Be sure to bring your own personal medicine and let us know if you have allergies to or cannot eat any specific kinds of foods.
Sunglasses are great for the afternoon bright sun.
Bring along a scarf for warmth and use as a dust filter if needed. A flashlight is nice. There is no light switch out under our stars in case mother nature calls in the middle of the night. A pair of gloves is nice for those cold frosty mornings and will help to protect your hands from the rough work you may want to participate in. You are welcome to bring your own favorite brand of 'frost repellent' for the after hours relaxation but we ask that good judgement be used.