When temperatures soar, especially combined with high humidity, people are at risk for heat-related illness including heat exhaustion and heat stroke.
While it’s best to avoid going outside in extreme heat, not everyone can stay inside. Whether you work outdoors or need to get in your exercise routine, there are ways to reduce your risk of developing heat illness.
Michael Redlener, MD
In this Q&A, Michael Redlener, MD, Medical Director of the Mount Sinai West Emergency Department, explains how heat can affect you and how to stay safe.
What are the risks of being active outdoors when it’s very hot?
If you are exercising or working outside, your body is working harder and your metabolism (internal process of converting food to energy) increases. Normally, your body can regulate the internal temperature even as your metabolism increases. However, when it is hot outside, the high environmental temperature makes it harder for your body to regulate its internal temperature, putting you at a higher risk of increasing your body temperature to dangerous levels.
Who is most at risk?
People who are 65 or older, children, people who have disabilities, and people who are generally working outside or spending a lot of time outside have a higher tendency to get heat illness. People who are overweight, on certain medications, living with heart disease or mental illness, and people who drink alcohol, are all at risk. Having a sunburn also increases your risk because it reduces your ability to control your temperature through your skin’s normal mechanism.
Concerning medications, certain drugs can affect your body’s ability to process heat, so it’s important to consult your doctor if you plan on being out in the heat. The Centers for Disease Control and Prevention provides guidance on heat and medications.
What signs indicate I’m developing heat illness when being active in the heat?
There’s a range of conditions to watch for. Painful heat cramps caused by dehydration and too much sweating are usually the first sign of danger. If you experience heat cramps, stop any physical activity, move to a cooler place, drink water or a sports drink with electrolytes, and wait for the cramps to go away before you restart physical activity.
If cramps last longer than an hour, or if you are for some reason on a low sodium diet, or if you have heart problems and these symptoms continue, seek medical help. If it progresses, it becomes heat exhaustion. You will experience heavy sweating, and feel cold and clammy. You may have a fast and weak pulse, some nausea or vomiting, and muscle cramps. You will also experience general fatigue and tiredness, dizziness, possibly a headache, and you may even pass out.
If this happens to you or someone else, move to a cooler place and loosen your clothing. If possible, apply cool wet cloths to your body or get into a cool bath to reduce your body temperature. Sip water if you feel nauseous, and to make sure you’re staying hydrated. If you are vomiting and can’t stop, or if your symptoms are getting worse or lasting longer than an hour, seek medical help.
How does heat stroke differ?
The next stage after heat illness is heat stroke, the worst heat-related medical condition that can happen to you. During heat stroke, your body temperature is 103 degrees or greater. Not only will you experience a headache, dizziness, and nausea, you also become confused. You don’t know where you are, or possibly even who you are, and you can pass out. Heat stroke is an extremely dangerous condition that can lead to permanent brain injury, and even death. If you are exercising and become confused or can no longer function, or notice this happening to someone else, get to a cooler place quickly and call 911. If possible, apply cool cloths or take a cool bath to get that temperature down.
How can I change my exercise routine to reduce my risk?
Here are some things you can do to reduce your risk:
- Limit outdoor activity as much as possible, especially during the middle of the day, the hottest period. If you need to exercise outdoors, do so in the early morning (before 10 am) or evening (after 4 pm).
- Wear sunscreen—SPF 30 or higher.
- Start slow and pace your activity, and slowly pick up the pace as you can tolerate.
- Keep hydrated during and after your workout.
- Wear loose, lightweight, light-colored clothing, which absorb less heat.
How can I stay properly hydrated?
There are a number of ways to make sure you drink enough fluids.
- Bring a water bottle and drink more water than usual.
- Drink sports drinks with electrolytes to maintain a balance between water and salt in your body.
- Don’t wait until you’re thirsty to drink. Once you are thirsty, you’re already dehydrated.
- Avoid very cold drinks, which can cause stomach cramps due to the dramatic shift in body temperature during extreme heat.
- Avoid very sugary or alcoholic drinks, which increase dehydration.
Any other suggestions on what I can do if I work or do physical activity outdoors?
If you have to be outside during the hottest hours, have a plan about what you are going to do should you start feeling badly. If you are with someone, such as a friend or coworker, check on each other to stay hydrated and get help if medical attention is needed.