Heat illness and dehydration: symptoms, causes, and prevention

As temperatures rise, so does your risk of heat illness and dehydration.

This is something I commonly see on the sidelines during spring HS and club sports like football, soccer, beach volleyball, and track. But this is not just an athlete issue. Heat illness can affect anyone spending time outside, including runners, hikers, and people doing yardwork or manual labor.

This past weekend, I worked a 7 v 7 football tournament and saw multiple athletes dealing with dehydration. Kids were coming off the field dizzy and overheated. A few had not eaten breakfast, and several did not even bring water.

One moment that stood out was a coach who realized about half of his team showed up without water. He paused the start of the game and ran to the vending machine to buy each of them a bottle before they stepped on the field.

That is what preparation should look like. Not reactive once symptoms start, but proactive before it becomes a problem.

Most heat-related issues are preventable with the right approach.

Heat illness symptoms to watch for:

Heat illness exists on a spectrum. It can start mild and become serious if ignored.

Common early signs include:

• Excessive sweating

• Fatigue

• Dizziness or lightheadedness

• Headache

• Nausea

  
  

If symptoms progress, it can lead to heat exhaustion or heat stroke, which is a medical emergency.

Dehydration and electrolytes: why water is not enough

When you sweat, you lose both fluids and electrolytes like sodium. Your body also burns energy in the form of glucose (sugar) during activity.

If you only replace fluids with plain water, you can dilute your electrolyte levels. In more severe cases, this imbalance can lead to serious complications.

For prolonged activity in the heat, sports drinks like Gatorade or Powerade can be helpful. They replace both electrolytes and carbohydrates your body is using.

Water still plays an important role, but it should not be your only strategy when you are sweating heavily.

How to prevent dehydration and heat illness:

One of the most common mistakes is trying to catch up on hydration during activity. Prevention starts before you get outside.

Before activity:

• Drink fluids consistently throughout the day of and few days before

• Eat a meal with carbohydrates

• Avoid starting activity already dehydrated

During activity:

• Drink regularly, not just when you feel thirsty

• Include electrolytes if you are sweating

• Take breaks and use shade when possible

• Wear light colored, breathable clothing and a hat

Who is at higher risk for heat illness?

Athletes are commonly affected, but they are not the only group at risk.

You may be at higher risk if you:

• Exercise outdoors

• Work outside

• Spend extended time in the sun

• Are not acclimated to the heat

Certain populations are also more vulnerable, including:

• Older adults

• Young children

• People with underlying medical conditions

• Those taking medications that affect hydration or temperature regulation

Bottom line:

If you are going to be outside in the heat and sweating, you need a plan.

Hydrate ahead of time. Eat before activity. Replace both fluids and electrolytes while you are out there.

Most cases of heat illness and dehydration are preventable with better preparation.