One thing they didn't mention is that all stimulants can wreck heat tolerance, because they tend to speed up the heart and tamper with the smooth muscles which control blood vessels. (Conversely, depressants slow down the body, so they can magnify effects of and sensitivity to cold.) Think about how many people take caffeine without considering it a real drug, and you can see why they faceplant into the pavement. Alcohol is another bad idea in hot weather, but for slightly different reasons; although it's technically a depressant, it has a hyper phase, it triggers the flush response, and it also dries out the body.
Alcohol and caffeine are things that most people can choose avoid. The other stuff, not so much. As time goes on, temperatures are rising due to global warming, which will make these drugs less and less safe to use.
That leaves people relying on other methods, such as:
* Drink before you feel thirsty.
* Eat salty things if necessary to stimulate thirst. You need more salt if you're sweating anyway. The only time I crave salty things is summer, and I deal with it by eating 3-4 potato chips at a time.
* Choose water, hydrating drinks like cucumber cooler or coconut water, juice, or sport drinks free of stimulants.
* Stay out of the heat, and especially out of direct sun, as much as possible. Short events are go or no-go, but you may be able to aim for the less-broiling morning or evening hours. With things like zoos, you can choose to go in spring or fall when temperatures are more reasonable.
* Learn how your body responds to heat. Symptoms can vary between people. After you've keeled over a few times, you should figure out where your thresholds are and when to quit. Most people can estimate their time per level of heat, and when they should just stay the hell home. If you take as-needed heat-affecting drugs, however, you may need different sets of thresholds for when you are on and off them.
* If you suck at gauging when you are overheating, which I do, enlist spotters among your friends/family to help you identify when that is happening. They should know what things help and what don't or make it worse. They should be prepared to defend you if necessary from outside helpiness. "This is a known condition and we are following a treatment plan" will make most people shut up and leave you alone; if not, that's a sign to scram if you can move at all.
* Ancestry matters. Dark skin may protect against solar radiation, but it also absorbs more heat. Fair skin has less protection but absorbs less heat. Much the same is true of dark vs. light hair. People whose ancestors lived in cold climates tend to be fatter and more compact, which can be a real hardship for heat dispersal. People whose ancestors lived in hot climates may have better resistance to heat. So if you are in a mixed group, be aware that sun and heat tolerance may vary a lot.
* Know where the air conditioning is. Right now, this is really hard because nobody's handling it as a survival resource yet. They've just started putting out cooler stations in the last few years. Well, some of those aren't real air conditioning. Do your best to know where there is genuine refrigeration at events. Just asking about this at events will boost the speed of deployment, because the more people who ask, the sooner organizers will realize it's needed. We need a basis of requests and established accommodations before the ADA will have grounds to step in and insist on meeting those needs.
* If you organize warm-season events of any kind, have a cooler station. At minimum you need shade, drinking water, ice, fans, paper towels or shop rags, and seating. Preferably, have a first aid person with a kit and a cell phone, and real air conditioning. Additional beverage types such as fruit coolers and sport drinks will serve a wider audience, because recovery needs can be very specific. Salty snacks, ideally made with sea salt for wider mineral content, will fix salt shortage from sweating. (Salt pills are too much for most people.) Mister fans are totally awesome and much more effective than plain fans, if you can find and afford them. Mister tents also help. Make the cooler station FREE and advertise the hell out of having it. If you have multiple buildings with air conditioning, mark them on your site map. This is cheaper than needing an extra ambulance and crew just for the heat afflictions on top of regular accidents.
* Also, organizers can help by minimizing the consumption of alcohol, caffeine, and other things that raise the risk of heat stress. Either don't serve them at all, or post a sign warning people of that specific hazard. Preferably, serve hydrating beverages instead such as water, fruit/vegetable coolers, and sport drinks. Reduce disappointment over no or limited alcohol by offering fanciful nonalcoholic drinks that people rarely get to try.
* First aid staff at warm-weather events should know to ask about drug use -- including caffeine and alcohol! -- if people present with heat stress symptoms. The main thing you'll be asked to hand out that's a high risk is the antihistamines. Make sure clients understand the heat risk before they take those.
* This is the one that really sucks: you need a drop threshold. If the temperature (and keep an eye on the subjective temp, not just the objective one) reaches a certain point, it is not safe to go out no matter what. Think about your personal body and what that is for you. Organizers, think about a cancellation threshold for heat just as you would for any other dangerous weather. You'd hate having someone drop dead during your event, so do what you can to avoid it. Some of the cluster kills we're starting to see are at things like sporting events, which makes them preventable. In general, if there's a heat advisory, it's better to cancel, and if there's a heat warning for essential travel only, then you should definitely cancel. But those are usually set higher than is safe, and sensible people should tap out at a lower temperature.
* Share the knowledge! Right now, most of the folks who know how to handle heat stress are first responders or folks with a genetic sensitivity. But we're moving into a time when higher temperatures will hit more people, and those folks have no idea what's going on. Teach body awareness and heat survival skills. Chances are you won't know when, but you will save lives with this if you teach more than a couple dozen people, because each person who knows can protect everyone around them.