Several years ago, our family had the good fortune to visit Quebec, Canada. I wanted to climb Mont-Saint-Hilaire, especially because of the pegmatite(s) found there. (See our Morefield mine project; that mine follows a pegmatite in Amelia, Virginia.) Our family walked together regularly, so this hike should not have been excessive.
As a family, we took a photo about 15 minutes into the hike, next to Lac Hertel. 30 to 45 minutes later, I began to feel quite ill. Despite my frustration, for whatever reason I knew I couldn't just press on with my heart racing the way it was. Because my phone (with an international plan) was charged, and I didn't want the family to miss the peak, I suggested that they leave me where I was.
Please note: While a further crisis did not occur to me on the mountain, this was clearly an unwise notion. Unfortunately, at that point I had not been diagnosed with Hereditary Alpha Tryptasemia Syndrome (HATS). Additionally, while I had been diagnosed with a complicated case of neurocardiogenic syncope (NCS) with cardiac block, I did not realize I was also having tachycardia events on a regular basis. This lack of diagnoses led me to overestimate my capability.
A passing walker mentioned that it was only 30 minutes to the peak, from where I was. This would mean that my family should be back to me within about 60 to 70 minutes (accounting for time to enjoy the vistas and to take photos from the peak).
The area where I was alternatively sitting and standing was rather dense. If I moved even a few paces in any direction, I no longer had cellular coverage. At any rate, I could not contact my family, because they did not have coverage. And there were spider webs every foot or 2. I'm not particularly afraid of spiders, but I am very allergic to their bites.
I waited an hour, but they didn't return.
I waited a 2nd hour, but they didn't return.
I waited another 30 minutes, and it was starting to get darker. In desperation, I started walking back toward the entrance. (It's possible that they had become confused and returned on one of the other paths.)
After 20 minutes of walking, my 2 sons overtook me. They explained that my daughter had fallen near the top of the peak, spraining her ankle. She and my husband were making the painful way down very slowly.
Relieved to find anyone, yet concerned, the boys and I made it to the entrance and spoke to the rangers. Using my limited French, I explained that my daughter needed help, and they agreed to locate the go-kart. However, as they found someone to handle the search and got the go-kart ready to leave, my daughter limped in, partially carried by my husband. We were one relieved family to all be together again.
On the way back to the hotel, I became violently ill. After vomiting, I was insanely chilled and was shaking violently, despite the August heat. The family passed every blanket and jacket available to me, to no avail. I remained ill the rest of the night. My daughter's sprain wasn't too difficult, and the next day, we were able to resume our vacation at a slowish pace. However, the next evening my son who has HATS became violently ill overnight, and we experienced our first Canadian hospital. He was quite sick for a couple hours, then all of his vitals normalized.
Once I was back home and had access to my St. Jude's Merlin unit, which could interrogate my pacemaker, my electrophysiologist could tell my heart had been in tachycardia.
I'll never know for sure what caused all of these issues. Altitude sickness? Allergic reaction? Simple exertion? An over full histamine cup? There is no such thing as "proper planning" with HATS and dysautonomia/NCS--at least not if you'd like to be adventurous.