I was told the body can acclimate to cold - see the divers in Amsterdam that slowly practic - and is used to treat spinal injuries if quick and used on the football fields or cold IV drips. You move the heat towards organs - remember humans have outsized brains using 20% of the energy. Your body comes with heat by sweating but you can have https://en.wikipedia.org/wiki/Heat_stroke

The chronically ill and elderly are often taking prescription medications (e.g., diuretics, anticholinergics, antipsychotics, and antihypertensives) that interfere with the body's ability to dissipate heat.

Patient works a mechanic job with no AC but has ample fluids. A heatwave sets in and because he is older working on cars from the 1990s could be on anyihypeetensives. Patient takes antipsychotics for biplolar and his job AC does not cool days with "feels like" temperatures of 115F.

Patient takes antipsychotics and stopped catching "a case of the handcuffs." Started to drink and loses air conditioning but reasons that it is winter so who cares? Did not check the forecast its a record 17F above normal temperatures. When you have higher Tmin 4am temperatures - obvious we have too many grenhouse gases - and lose air-conditioned areas people cook.

Patient is elderly and a storm comes while residing in a Florida nursing home. A politician on the TV is talking about "death panels" to scare people away frok more - not less coverage. Storns that used to be known days in advance my adult life are now Acupulco with no warning. https://www.google.com/amp/s/www.nbcmiami.com/news/local/trial-begins-for-owner-of-hollywood-hills-nursing-home-hurricane-irma-deaths/2966597/%3famp=1