Once again the 3-Hs of running hell rise in the east to trample racing times, shorten training runs and leave us tired and miserable. Hazy, hot, humid weather returns to western PA.

The National Weather Service reports that heat has been the number one weather-related killer in the US over the past 30 years. According to the Center for Disease Control, 400 Americans die each year from summer’s heat and humidity. While many who succumb to the heat have pre-existing health issues, these statistics serve as a warning to runners who pride themselves on exercising in any and all weather.

When running, the body releases 75 percent of its energy in the form of excess heat. Dissipating that heat isn’t a problem at temperatures of 70 or less, higher if the humidity is low. But as temperature and humidity rise, the body’s cooling systems just can’t keep up, setting in motion a dangerous chain of events.

First, millions of sweat glands are called upon to reduce body heat through evaporation. Blood vessels dilate to circulate blood quicker and closer to the skin. The heart beats faster since blood flow per beat is reduced. Since survival becomes the body’s first priority, running performance suffers. Because blood is diverted to the skin, it isn’t available to muscles. This causes fatigue and possibly muscle cramps. Heart beat approaches maximum but as blood thickens, it’s harder to circulate.

At some point the body’s systems can’t keep up with demands. Internal temperature continues to rise. If we choose to continue, we risk heat exhaustion or worse, life threatening heat stroke.

The first step in avoiding serious heat injuries on the run is prevention. Check the National Weather Service’s Heat Index (www.weather.gov/safety/heat-index) before you run. If the numbers are in the danger zone, postpone your run or head for the treadmill. In conditions that advise extreme caution or danger, modify your plans accordingly.

If you choose to venture out, pre-cool by taking a cold shower or dip in the swimming pool. Dress in loose-fitting, light-colored clothing. Stuff some ice into your sports bra or under a hat or bandana. Drink water or sports drinks for longer runs — or if you are a salty sweater, before you run and carry some with you if you won’t have access to fluids along the course.

If you had planned an easy or steady-paced run, run by heart rate, not pace. For scheduled long runs, run for time, not distance. Depending on your particular response to heat, slow your pace by 30 to 90 seconds per mile. Run short loops instead of one long course to have access to fluids and cool air and stop running if you begin to feel effects of the heat.

Modify your running route to maximize shade. A run through the woods is not only cooler but lessens exposure to the third H in the summer mix --- haze.

That summer haze is ground level ozone, a product of nitrogen oxide and volatile organic compounds (VOCs) exposed to heat and sunlight. Ground level ozone can trigger asthma attacks, wheezing, coughing and increased susceptibility to respiratory illness. Breathing this toxic air can permanently damage the lungs, and runners are particularly vulnerable because they inhale deeper and process more air.

To avoid ground level ozone exposure, run early in the morning. Stay away from major highways. Run indoors on Ozone Action Days. Check the area’s daily or forecasted air quality at Airnow.gov.

Upcoming events

Wednesdays, 6:30 P.M.: Run Club Group Run, Cranberry Township. Run from Mojo Running Store. 724-772-2808 or www.mojorunningpittsburgh.com

Saturday, 7:45 A.M.: Butler YMCA Outdoor Triathlon, Moraine State Park. Triathlon for individuals ages 16 and older or teams. 724-287-4733 or bcfymca.org

Saturday, 9 A.M.: Elk County Classic 5k, Ridgway. Starts at Clarion-Little Toby Trailhead. 824-776-2413 or bczappa504@comcast.net

Saturday, 9 A.M.: Heritage Day 5k, Greenville. Part of Heritage Day festivities. More than 50 door prizes. 724-815-6983 or jas26mrun@msn.com

July 11, 7 P.M.: Dam Race (Quad II), Sharpsville. Second race in Twilight Quad series run on Trout Island Trail. 724-866-1374 or smc@runhigh.com

July 13, 7 P.M.: Emlenton Summer Festival 5k, Emlenton. New course. 724-867-0089 or brendabeikert@gmail.com

July 14, 9 A.M.: Fireman’s Mud Run 5k, Fairmont City. Benefits volunteer fire companies in Armstrong, Clarion, Jefferson and Venango counties. 814-229-8127 or www.distantareavolunteerfiredepartment.net

July 15, 6:45 A.M.: ERC Presque Isle Half Marathon, Erie. One loop of Presque Isle State Park starts at Beach 1. 814-881-0600 or davemcomi@gmail.com

July 15, 7:30 A.M.: Trail Blazer 5k & 15k, Meadville. 814-853-8572 or www.ernsttrail.org

July 15, 8:30 A.M.: Hermitage Arts Festival 5k, Hermitage. 724-981-6950 or bgriffin@hermitage.net

July 15, 8:30 A.M.: Elorapalooza 13th (and final) Memorial 5k/ 1-Mile Run, Walk or Lollygag, Allison Park. Starts at North Park Lodge, post-race picnic. 412-608-2134 or www.elorashope.org

July 17, 7 P.M.: Arts & Education at the Hoyt 5k Color Run, New Castle. 724-652-2882 or communications@hoytartcenter.org

July 18, 7 P.M.: 16th Annual Kalajainen Klassic 5k, New Castle. Run in Cascade Park. 724-652-5105 or Dreed055@aol.com

July 20, 7 P.M.: GNC Live Well Liberty Mile, Pittsburgh. One mile run in various heats. Libertmile.org

July 21, 9 A.M.: Curwensville Susquehanna Classic 5k Race, 5k Walk and 10k, Curwensville. 814-236-3455 or sharonike@verizon.net

July 25, 7 P.M.: UPMC Horizon 5k, Greenville. Race 3 of Twilight QUAD. Also kids’ half mile run at 7:45 P.M. 724-866-1374 or smc@runhigh.com

July 29, 7:30 A.M.: Sweet Corn Challenge Run, Richfield, OH. Choice of 5k or 10k timed runs, 3k jog or walk. Kids 1k fun run obstacle course starts at 9:30 A.M. Post-race catered brunch with food, drinks, draft beer. 330-659-3300 or Sweetcornchallenge.com

July 29, 8 A.M.: Run with the Deer Flies 15k/25k, Penn Run. Trail runs through Yellow Creek State Park. 724-442-8388 or dwalker100k@gmail.com

July 29, 8:30 A.M.: Pass the Pancakes 5k Race and Fun Walk, Waterford. Run through rolling farmland starts near Picnicana Park, free post-race pancake breakfast. 814-460-0286 or schrumpfc@fortleboeuf.net

August 4, 8 A.M.: Armstrong Habitat for Humanity Raise the Roof 5k, Kittanning. elizabeth@armstronghabitat.org or www.armstronghabitat.org

August 4, 9 A.M.: St. Barnabas Free Care 5k, Gibsonia. Post-race party with music, food, beer. 724-625-3770 or stbarnabashealthsystem.com/stbarnabas5k

August 5, 9 A.M.: XTERRA Appalachia Triathlon, Indiana. Staged at Day Use Beach Area of Yellow Creek State Park. 814-397-4316 or doug@adventuresports.com

Race results

Glacier Ridge 50 Miler, May 12: Jeffrey Adams, 1st Overall M, 7:52:38; William Huber, 2nd Overall M, 8:31:02; Anna Piskorska, 1st Overall W, 9:07:57; Brian Buchan, 9:52:31; Adam Shoup, 10:47:11; James Wrubel, 11:48:38; Murray Hofmeister, 12:36:07

Glacier Ridge 50 Mile Relay, May 12: The Glacier Pacers, 6:51:29; Trail Mix, 9:42:17; Hank Smiles, 10:01:42; Old Enough to K Better, 10:10:06

Glacier Ridge 50k, May 12: Sean Hulburt, 1st Overall M, 4:28:24; Melissa Pastore, 1st Overall W, 6:01:31; Jeff Lynn, 6:33:10; Michael Bossola, 6:41:08; Luke Eckley, 6:51:32; Eric Shumaker, 6:57:51; Morgan Siebka, 7:21:27; Vincent Trigili, 7:23:33; Mark Casteel, 7:26:49; Chad Coblitz, 8:25:31; Joella Baker, 8:35:01; Connie Hoffer, 8:35:46; Will Gramlich, 9:41:45

Glacier Ridge 30k, May 12: Jamison Dohn, 1st Overall M, 3:02:19; Jamie Eakin, 1st Overall W, 3:11:47; Adam Stillwaggon, 3:29:59; Meredith Colaizzi, 3:32:00; Jessi Drayer, 3:47:36; Dan Tack, 4:09:39; Matthew Kephart, 4:12:31; Adam Fencil, 4:12:57; Ted Zablocki, 4:12:58; Gary Hayden, 4:28:00; Matthew Garraux, 4:33:17; Ruth Werne, 4:37:40; Alexander Sonson, 4:39:34; Daniel Beggs, 4:40:28; William Woods; Adriana Alatorre, 5:00:17; Jonathan Delcamp, 5:03:23; Corey Eckenrode, 5:05:06; Scott Grooms, 5:17:59; Robert Crawford, 5:21:40; David Adams, 5:33:04; Kristy Marcinko, 5:45:58; Janelle Fumerola, 5:59:31; Elizabeth Dickey, 6:08:25; Kristi Trigili, 6:12:21; Tim Beggs, 6:49:13

Komen Race for the Cure 5k, May 13: Ryan Torbic, 1st Overall M, 18:36; Ava Pietrzyk, 1st Overall W, 20:14; Linsey Schnur, 1st 30-39 W, 21:20; Debbie Courtney, 3rd 50-59 W, 26:18; Marcia Semple, 2nd 70+ W, 42:35; Jessica Price, 23:33; Jake Parry, 24:16; Max Sybert, 25:00; Melissa Burkett, 26:55; Brian Shuttleworth, 27:50; Haden Shimko, 28:04; Jim Sutterfield, 28:59; Michelle Brochetti, 29:55; Laurel Sutterfield, 30:12; Joseph Shimko, 30:24; Beth Sutton, 31:01; David Gaus, 31:54; Valerie Wolenter, 32:00; Jennifer Eckenrode, 32:27; Melissa Eckenrode, 32:29; Tim Bollinger, 32:39; Marsha Haley, 32:46; Jeffrey Banyas, 33:19; Julie Banyas, 34:14; Joann Banyas, 34:14; Benjamin Frederick, 34:36; Nicholas Babeo, 34:39; Natalie Babeo, 34:40; Ryan Babeo, 34:41; Caitlin Brunner, 34:55; Michele Carson, 35:04; Terry Melis, 36:15; Ashley Gibson, 36:28; Nash Leslie, 36:29; Ann Cheman, 38:20; Domenic Lombardo, 38:52; Jennifer Toy, 39:07

Fueled by Fire 5k, June 9: Dan Carlino, 1st Overall M, 17:57; Ryan Steigerwald, 2nd Overall M, 19:38; Michael Baumgartel, 3rd Overall M, 19:54; Julia Zalenski, 1st Overall W, 21:12; Abby Kreber, 2nd Overall W, 21:24; Christina Beaver, 3rd Overall W, 23:40; Owen Schessler, 20:34; Gregory Jones, 22:29; Anuj Kaul, 23:24; Dan McCauley, 23:47; Jinny Hertweck, 23:55; Eliza Matusea, 23:56; Rebecca Roberts, 24:28; Janel Kasowski, 24:31; Tom Toplak, 24:48; Kelley Baumgartel, 26:08; Steve Smith, 26:14; Clayton Morrow, 26:32; Bruce Barnes, 26:37; Ryanne Palermo, 26:54; Daryl Brandon, 26:58; Erin Hart, 27:04; Meredith Ashbaugh, 27:23; Keelin Schessler, 27:37; Zach Mullinax, 27:43; Jim Roach, 27:51; Amy McCauley, 28:12; Cassandra Roach, 28:22; Katie Jamison, 28:44; Bodey Balfour, 28:53; Rachel Bobko, 29:16; Ronni Morrow, 29:20; Vicki Brendlinger, 29:40; Manal Jordan, 30:00; Hillary Gaertner, 30:05; Luke Freshwater, 30:51; Tricia Mullinax, 31:45; Barb Barnes, 32:55; Zachary Jordan, 36:16; Erika Morrow, 37:52; Casey Morrow, 37:52; Karen Morrow, 38:03; Shelley Wood, 38:04; Giovanni Vignolo, 38:22; Beth Ann Skinner, 39:02; Christine Sheehy, 41:07; Nicole Campbell, 42:35; Nick Campbell, 42:35; Giovanna Porta, 45:23; Reza Liaghat, 46:52; Paul Kasowski, 46:52; Kate Ashbaugh, 47:40; Domenique Roach, 48:08; Rhea Sciarrino, 49:18; Lisa Marie Weinzetl, 49:18; Peg Ganter, 50:37; Jessica Malewski, 50:37; Candence Mathews, 51:08; Russ Ford, 51:08; Mike Sheehy, 51:08; Dennis Clark, 51:08; Bev Tumpa, 51:30; Diane Altic, 51:30; Michele Bobko, 54:36

Send comments and suggestions: Patricia Neubert. Phone 724-352-4395. Email lotzak@consolidated.net

Patricia Neubert is a running columnist for the Butler Eagle