What is the ruling on waking a female colleague for prayer via phone?

It is not appropriate for a young man and a young woman to cooperate in waking up for Fajr prayer via phone, exchanging thanks and supplications, because Satan gradually lures a Muslim towards evil, and he may beautify for them a good deed mixed with what is unlawful. Each of them can wake up for prayer using other means, such as an alarm clock, or by cooperating with someone of the same gender, to avoid temptation. The Prophet, peace and blessings be upon him, said: "I have not left behind me any temptation more harmful to men than women."