CI MED Expert Viewpoint: What are the Signs of Heat Stroke?

Multiple heat waves blistering across the globe this summer — including one in which hundreds of Hajj pilgrims died — and proposed Biden administration regulations for outdoor workers have highlighted the public health impacts of extreme heat. Dr. Holly Rosencranz, an internal medicine physician and a clinical teaching professor in the Carle Illinois College of Medicine at the University of Illinois Urbana-Champaign, talked with News Bureau biomedical sciences editor Liz Ahlberg Touchstone about the signs of heat sickness, how to prevent it, and what to do in a heat stroke emergency. With video by Andy Savage.

When is someone at risk for developing heat sickness? 

There are vulnerability factors and exposure factors. Exposure factors are the traditional or more obvious things that you might think about: Attending or participating in outdoor events, athletics, being an outdoor worker. Some indoor occupations can also require heavy work in hot conditions: Industrial factories, workplaces with hot ovens, or settings requiring wearing heavy gear can pose risks to employees. 

However, there also are vulnerability factors that increase the risk for heat sickness. Certain medical conditions put people at higher risk. They could be very young, elderly or pregnant. They could be on different medications or have chronic conditions or illnesses that lower their threshold to be impacted by heat. Even short durations of heat can impact these populations. 

One person in a hot environment may have no symptoms at all, while another does, because they don’t have the underlying vulnerabilities that the other person may have. So it’s very important to recognize this danger and to remove people from situations when they are at increased risk or starting to have symptoms of heat illness. Heat illness can progress rapidly and lead to heat stroke, which can be irreversible and fatal.

What are some of the signs or symptoms of heat sickness? 

Heat sickness presents across a spectrum. Heat-related illness might start with some mild, nonspecific symptoms, and it could progress gradually or evolve rapidly. Early symptoms may include flushed skin and muscle cramps. This condition may progress to heat exhaustion, in which the individual might start to feel very dizzy and could experience headache, heavy sweating, nausea, fatigue, and weakness.  

This can lead to the life-threatening condition of heat stroke, when the body has lost the ability to cool itself. Heat stroke is also characterized by altered mental status, such as lethargy and confusion, and can lead to seizures, loss of consciousness, and collapse. 

What should you do if you suspect that you or someone near you is experiencing heatstroke? 

As soon as somebody is starting to feel symptoms of heat stress — for example, fatigue muscle cramps, nausea or dizziness — the sooner that person is removed from the situation, the better, and the better the chance of recovery.  

Do anything possible to help start cooling a person with any level of heat illness: stop all activity; get them out of the sun or the hot setting; get them into a shaded, cool place; remove clothing; cool them with wet cloths on the skin; fan them; and call 911. Call 911 for any altered mental status or change of behavior, like if the person is becoming confused, lethargic or clumsy, or loses consciousness.

What are some things people can do to keep cool and prevent developing heat sickness? 

Prevention is a huge part of mitigating heat illness. First, one should be aware of the temperature and evaluate if emerging into potentially dangerous heat conditions can be avoided. If possible, move activities to a different part of the day when the heat is not as intense. Some people can't avoid being outdoors at the peak of heat, so staying in the shade as much as possible, wearing protective clothing that is loose and light-fitting and keeping well hydrated throughout the day are some of the things that one can do. Staying well hydrated is a very important aspect of adapting to heat. 

Fans can be helpful, but fans in extreme heat actually can have the effect of blowing warm air instead of cooling a person. Certainly, air conditioning is wonderful, but not everybody has access to cooled homes and environments. Hopefully, communities will provide resources such as cooling centers, programs to transport people to such facilities, and policies that support weatherizing homes for safer conditions. 

The advice I would give people is to be very aware of heat-related illness and not to try to power through. The other thing, and this is related to some policy and advocacy issues, is that employers must be aware of the need for their workers who work in heat conditions to have regular breaks, access to shade and cooling, regular hydration, and the ability to report illness without any repercussions. 

Are there other health effects of heat, beyond acute heat illness or heat stroke?

Heat is a widespread public health concern. We know that heat waves are increasing in frequency and duration. Heat waves impact our air quality and that has many downstream effects, such as worsening cardiovascular and respiratory diseases Prolonged exposure to heat can cause kidney disease, impact fetal and maternal health, and affect mental health. It impacts vector-borne diseases, water quality and water-borne diseases, and our food supply. These may not be as dramatic as an acute medical crisis unfolding in someone standing next to you, but these long-term effects are profound. 

Editor’s notes: To reach Dr. Holly Rosencranz, email harosen@illinois.edu.  

The original version of this article can be found here.