Immediate Mental Health Support

Emergency Referral &/or Mental Health Advice Sought ASAP from EdHat Community
An associate has had a house guest for the last couple of weeks. In that time she, the guest, has been very unstable mentally, and has had two or three psychotic incidents where the PD was called, the latest one having occurred recently, in the last couple of hours. PD will not summon an ambulance to take her to PHF psyche unit because it is continuously full. Guest is sitting this moment in the middle of the parking lot, half out of her mind while the sun is setting. What are some options for the guest to get some immediate help and to stay safe while waiting for that help?
I should add that guest refuses to reenter building due to her ongoing psychosis.