Updated: Jan 14, 2020
by Chris Palmquist
Although I just put away my coat a couple of weeks ago, it is now undeniably HOT here in the Chicago area. The dew points are high, the heat index is above 100 and the hot air presses on us from all directions.
The first real heat waves of the season are the most dangerous as we are not physiologically acclimated after a long cold winter. Each successive hot day makes the situation far worse as heat illness can be cumulative. Some have enhanced susceptibility to heat illness: babies, seniors, and those with chronic health conditions. Children who have not yet gone through adolescence are less able to sweat to regulate their body temperature. Pets are also at risk if walked on hot pavement or left in vehicles.
We endurance athletes test ourselves by training and racing in the heat. As we train, our body temperature, blood pressure and heart rate rise with normal athletic exertion. Add heat and humidity to this training session and our body can quickly lose the ability to stay in the safe temperature range. With increased sweat rate comes an increased need to hydrate and often we end a hot session in a somewhat dehydrated state - further stressing our body. But overhydrate and our electrolyte balance can become dangerously affected.
On most days, we end our session, go back to a cool house, drink a smoothie full of frozen berries to cool off and get on with our day just fine. But what if we have a second training session scheduled that same day? What if it has been hot for a week? When will we reach our limit and experience some level of heat illness?
Do not find that limit. Heat illness at any level is serious. Mild heat illness will cause you to feel poorly for a few days. You may be extra sensitive to heat and be unable to train above a recovery effort for a week or two. Serious heat illness can be life-threatening and result in a trip to the hospital. Even your efforts to stay hydrated in extreme heat can throw off your electrolyte balance – causing hyponatremia, kidney failure, coma and death.
If the heat is on in your area of the country, be cautious. Pay attention to how you feel. Respond quickly to any symptoms that your body is losing the battle of temperature regulation. Switch outside workouts to inside treadmills and bike trainers. Drink icy cold fluids with adequate electrolytes. Shorten or skip workouts so that you won’t get ill. Be smart – your life is worth it.