Had Vomiting, Taking Lisinopril. Have Orbital Edema, ARF, Heat Exhaustion. Help

i am a critical care nurse. My boyfriend has just started seeing a cardiologist and has a stress test and nuclear med test next week. He is taking 5mg lisinopril QD. He has always had a normal B/P until July when we were broke down on the side of the freeway for 6 hours in 115 degree heat. We had fluids, wet ourselves in sprinklers, and wound up in the same heat outside two more days due to further breakdowns-worst trip ever. I wound up in ER due to anuria and finally vomiting despite lots of water and Gatorade. I was given IV fluids and potassium . He was OK. It took us 2 weeks to recover-we had pedal and orbital edema , and food and drinks tasted funny ( electrolyte imbalance despite everything we did). We never had heat stroke, but definitely heat exhaustion and borderline ARF. He has had heat stroke twice in his past. He has had some heat intolerance and excessive diaphoresis since I ve known him, but since our trip from hell, it has been worse. Additionally, he has hypertension- SBP 130-180, DBP 90-110, HR 90-115, and always happens when he is outside in the heat (even for short periods of time, even in the shade, even with fluids. He will sweat excessively (I could wring out his shirt) He is asymptomatic. Once I get him home resting in th A/C, wet his head and neck, fan on, more fluids and rest, his V.S. normalize. This is an acute, heat, fluid-related situation as if his body is overreacting due to past heat stroke and this last episode in the heat on our trip. I m wondering if it could be an overreaction from the hypothalamus or pituitary gland, and if there are any tests and possible medications to check or help this. All of his labs have been WNL mulitiple times. He does not do any drugs, and has no medical history or problems. Other than the Lisinopril, he takes ASA 81 mg QD. I have attempted to look up this info on my own, with insufficient results. I would appreciate any professional input you can offer. Thank you for your time. Janiece E-mail: YYYY@YYYY