Ruth Ross, 57, from Hamilton in South Lanarkshire, passed out in sweltering temperatures on a trek near Palm Springs on Monday.
After collapsing, she was airlifted to hospital after her husband Chris called for help. She died soon after arriving at hospital.
The mother-of-three was a member of Parkhead Nazarene church in Glasgow, where prayers were said last night. A church statement said: "It has been such difficult news to hear and feel. We're coming together throughout the day at church to support one another and pray for Chris and the family."
Mrs Ross, who previously taught at Dalziel High School in Motherwell, North Lanarkshire, was also a governor of the Nazarene Theological College in Manchester.
Revd Dr Deirdre Brower Latz, Nazarene Theological College Principal said: "We were deeply saddened to learn of Ruth Ross's untimely death, she was both a College Governor and a good friend to so many of us.
"Godly and gifted, as a member of the Board of Governors she served as its secretary, a post which she held with distinction.
"She had sensitivity, passion for the college, was visionary and professional, and she was a vibrant contributor to our discussion and direction and will be greatly missed."
It is understood Mr Ross is still being treated in hospital in Palm Springs, where temperatures reached almost 40 degrees C (104F) on Monday.