a hot flash does not cause a loss of consciousness but people can simply faint (syncope) anytime. and for a variety of reasons. since this is unusual for you it would be prudent to discuss this incident with your medical provider -- someone who knows you your medical history and someone who has the ability to examine you and order any appropriate diagnostic tests.
can a hot flash cause loss of consciousness? . peri-menopausal one time only experienced sudden heat throughout whole body lost color in face then passed out.