Hello Bettina:
It is NOT safe for these birds to be outside during this kind of weather. These birds need a constant temperature between 70-80 degrees and NOT in direct sunlight. This can cause heat stroke or heat exhaustion. It is imperative that they get indoors into a controlled area. This can also cause respiratory issues for the birds. Now, don't get me wrong, the birds can be outside for a bit to get some fresh air and sunlight..but all day is NOT appropriate. It is also important to have FRESH CLEAN water for birds at all times. Bacteria will bloom in heated water especially if they get food or feces in the water. Please, tell this owner that she has to get her birds out of the sun and they should not be out unless the temperature is under 80 degrees. Good luck and let me know how you make out :)
animal care specialist
15+ yrs pet health care, breeder of English Mastiffs, barnyard, knowledgable aquarium keeper