> "Collapsed while hiking." The only way that can happen is with an interruption in blood flow, which means a clot or a bleed.
or just due to plain old heatstroke and/or going beyond your physical limit (on that given day and for you given overall condition for that day). You should at least have mentioned whether you know this hills. I hike a lot in the East Bay, and if i remember the Sat was pretty sunny.
"Going beyond your physical limit" -- what, exactly, does that mean? Thousands of times a day, people get on treadmills in cardiologists' offices, and are taken to their physical limit with a "maximal effort stress test." Even this doesn't precipitate life-threatening complications unless cardiovascular disease is present.
There are some genetic blood disorders that can cause sudden death during extremely heavy exertion (e.g. professional football drills) at altitude, but they are very rare in caucasians, and Berkeley's hills don't qualify as "altitude."
or just due to plain old heatstroke and/or going beyond your physical limit (on that given day and for you given overall condition for that day). You should at least have mentioned whether you know this hills. I hike a lot in the East Bay, and if i remember the Sat was pretty sunny.