Disclaimer: In no way is this medical advice. Running in the heat is very dangerous and should be taken seriously.
I have had a couple of runs in the heat this summer that have been overwelming. In the past I would get sick after, dehydrated but not quite heat exhaustion. You know that headache feeling you start getting. Then your body just feels like it's burning from the inside out. My skin feels like it's shrinking.
No run is worth your health. No PR is worth a chance of getting sick, collapsing or worse, dying. The body works on a delicate electrolyte balance that, when working correctly, is a rock star. Overload it too much and it collapses. If you feel it is too hot it probably is.
Saying that, there is so much good information for runners that we can run in the heat and run safely. I started doing research on it a couple of years ago when I started doing long runs in the summer. I also ran a 5K in some high heat that I wasn't use to and I was pushing myself to get a PR. I still remember laying on the grass after and thinking, "why couldn't I go faster and why do I feel so bad". I guess it never crossed my mind that you should run slower in the heat.
Runners World has great articles here.
Here is some great information about the warning signs from Runners World.
Recognize—and deal with—harmful heat ailments.
SPOT IT Spasms in the abdomen, arms, calves, or hamstrings
TREAT IT Stop running for the day; sip sports drink; gently massage the cramp.
SPOT IT Heavy sweating, headache, dizziness, nausea
TREAT IT Stop running; get in shade; sip sports drink; see a doctor if symptoms continue.
SPOT IT Confusion, rapid breathing, fainting
TREAT IT Stop running; call for emergency help; get in shade; cool skin with water.
Jeff Galloway also addresses running in the heat with this information from his Website.
Adjusting Race Pace for Heat: Estimated temperature at finish - Slower than goal pace - 8 min mile becomes...
55-60 degrees - 1% - 8:05
60-65 degrees - 3% - 8:15
65-70 degrees - 5% - 8:25
70-75 degrees - 7% - 8:35
75-80 degrees - 12% - 8:58
80-85 degrees - 20% - 9:35
Above 85 degrees - Forget it... run for fun
He does mention this has no scientific value, but I've found it to be pretty true.
I am posting about what works for me. How I have taken all the information that I have researched and adjusted it for my body and what it can handle. Everyone is different so play around with it until you can find the right combination and you will find yourself getting in that long run and not being sick or having a headache after. Keep in mind that humidity plays a big part in heat and I live in the desert and feel like I'm choking to death on the air if the humidity is over 20%. I also run anywhere from 4500 ft to 6500 ft above sea level which I think poses yet a different problem.
Always wear sunscreen. I usually put 30 spf on my body and 70 on my face and neck. If you can't be grateful for not having a sunburn, then you will be grateful for a few less wrinkles and no skin cancer when you are older. Plus burns dehydrate you really bad as the body sends all it's fluid to the burn site. Burns also make your body work really hard.
Hydrate. If I have a long run that I know will be in over 70 degree heat I will drink a lot of water and even a few NUUN or electrolyte drinks the night before and then one before I go in the morning. I'm not sure if overnight hydration works, but it works for me. When I'm running a relay and have to run 3 times in 30 hours I drink at least 32 oz of electrolyte drink in between.
Hat, cool clothes or whatever makes you feel comfortable.
Water. I take water and it's usually icy. I sip it so I don't get stomach aches. I also plan my run around a couple of gas stations with ice machines or a park where there is a water fountain to keep my bottle full.
Try to pick a shady run. Lesson learned up in Rock Springs. I had a long run that I couldn't start until about 11am. After refilling my bottle 4 times and cooling down in gas stations a couple of times I decided to stop. It was a good decision. The route had zero shade. I don't know my way around very well and I wanted to stay close to the apartment and parked my car so I had it available with frozen water bottles and energy chews. That was not enough, it just got too hot and finally at 93 degrees and almost 2 hours of running I called it a day.
I also learned about blacktop on my last run for Napa Ragnar. When I moved to the dirt I could physically feel it cooler on my whole body. I tried to stay on the dirt as much as I could to keep from boiling.
Get Wet. Poor some water on your head during a race while sipping some Gatorade at water stops. A little water on the head always feels refreshing and cool.
Electrolytes. I have just started trying Salt Sticks. I had them in Napa and had one before my runs. I happen to have one in my race belt when I ran that very hot and overwhelming last leg and I took it at mile 5. I really think they help. They don't take up much space, don't hurt my stomach and after that run (I had one before and one after also) I did not get sick. I needed about a 45 minute recovery cool down and then I was golden!
Last but not least, if it's too hot just go for the treadmill.
After. Rest in a cool place and I usually drink one electrolyte drink if I was super sweaty. Get your usual post run nutrition and recovery.
I had a 5K this summer and I really wanted to PR. I remembered the last 5K in the heat and what a pain it was so this time I decided to heed the advice and slow down my pace. I had ice water and dumped some water on my head mid race. I didn't PR but I enjoyed the race!
Just remember, anytime it's a little hotter then comfortable then really pay attention to your body and your fluid intake. I had some awful hot runs this summer but I never suffered that heat headache that I use to suffer from.
Take care of your body and it will take care of you!
Any questions you have about how your body is reacting to running in the heat then see your regular physician. Hopefully a physician that understands how important running is!