My Lady Friend Is A 58 Year Old Female Living

my lady friend is a 58 year old female living in south central texas. Temperatures last week exceeded 90 degrees. On the golf driving range, face flushed over heated.. sweaty... slight nausea,"felt weak and over heated".. third episode. one day golfing, felt dizzy, on vaction in mexico overheated while at beach also flush and exhausted. denies chest pain or shortness of breath, no cardiac history. HX of HTN bp ranges 120-160/ over 60-70 only significant medical his is HTN and Melanoma 2001-2005