Recognizing the Warning SignsHeat exhaustion and heatstroke share many of the same warning signs, with a few key differences. “To the naked eye, it’s difficult to distinguish between heat exhaustion and heatstroke. To differentiate between the two, you need to know if the person’s brain is working well and what their body temperature is,” says Roberts.According to StatPearls, the main differences between heatstroke and heat exhaustion are eventual organ damage and the symptoms affecting mood, thinking processes, and coordination.[5]Symptoms of HeatstrokeThe Cleveland Clinic adds that signs of heatstroke also include:[6][7]Hot, red, dry, or damp skin, if the person has been exercisingFast, strong pulse, becoming weak as heatstroke progressesHeadacheDizzinessNauseaPassing outMovement and balance issuesLung crackles or abnormal breathingMaking very small amounts of urineWeaknessSymptoms of Heat ExhaustionSigns of heat exhaustion include:[8]Heavy sweatingFast, weak pulseNausea or vomitingMuscle crampsTiredness or weaknessDizzinessHeadachePassing outCool, pale, clammy skinElevated body temperature, but typically less than 103 degrees FHow to Treat Heat Exhaustion or HeatstrokeSince heat exhaustion and heatstroke are separate medical conditions, the treatments differ. If you suspect that you or someone you know is suffering from heat exhaustion, a few steps can help that person to start cooling off and rehydrating while waiting for medical help.Heat Exhaustion TreatmentIf possible, the Cleveland Clinic recommends the following:[9]Drinking cold beverages that don’t contain any alcohol or caffeineCooling off in the shadeStaying indoors with air-conditioning or a fanTaking a cool bath or showerRemoving excess clothingRest is also key because it reduces strain on the cardiovascular system and helps stabilize body temperature.Heatstroke TreatmentHeatstroke, on the other hand, is a life-threatening condition that requires emergency treatment. Without medical intervention, the condition can quickly cause brain, heart, kidney, and muscle damage or failure, and it can be fatal.When caring for someone you suspect has heatstroke, the first thing you should do is call an ambulance. While you wait for medical professionals to arrive, you can begin to try to lower the person’s body temperature in the following ways:Move the person to a shaded or air-conditioned area to cool down.If possible, place them in a cool bath or shower or cool them with water from a garden hose. According to a meta-analysis of 63 studies on heatstroke treatment methods, submerging a person in cold water — about 34 to 63 degrees F — is the most effective method to lower core body temperature.[10]Importantly, Mayo Clinic advises against giving a person with heatstroke anything to drink.[11] Many people with heatstroke have an altered mental state, which could make it unsafe for them to drink fluids.Preventing Heat-Related IllnessAccording to Barrak Alahmad, MBBS, a physician and mission scholar in the faculty of public health at Kuwait University and a PhD student at Harvard University’s T.H. Chan School of Public Health in Boston, heatstroke and heat exhaustion are completely preventable.“High temperature, high humidity, and extensive physical activity trigger both,” he says, noting that as a first step, early warning systems can help alert the public of extreme-heat days so they can prepare to stay out of potentially dangerous heat.Knowing the heat index, which combines heat and humidity to mark how the temperature really feels, is key to understanding how well your body will be able to cool itself, Dr. Alahmad explains.[12] Sweating is one of the main ways the body expels excess heat. When sweat evaporates from the skin, the body cools. If the air already contains a lot of moisture, less sweat can evaporate. Essentially, humidity takes away the body’s natural cooling system, says Alahmad.Roberts says it’s important that people respect their own limits regarding heat. “An expectation or obligation to perform can complicate this, as is the case sometimes in football. You may push yourself because you don’t want to get cut from the team,” he says. While some may tolerate the heat or exercise more than others, no one is immune to heatstroke and heat exhaustion. For example, heatstroke during exercise is one of the leading causes of death in high school football players, with 61 deaths occurring between 1960 and 2017, according to a study.[13]According to the National Institute for Occupational Safety and Health, workers who can’t avoid the heat can take steps to protect themselves from heat stress.[8] In addition to the precautions anyone should take to avoid heat-related illnesses, workers should try to reduce the effects of extreme heat in the following ways:Gradually build up to heavy exertionTake breaks as often as possible in a shaded or cool areaBe aware that protective equipment required by the job can sometimes increase the risk of overheatingIf you need to be outside on a hot day, be sure to wear:Light clothing (both in color and fabric)A hatSunscreen“Getting into air-conditioning for as little as 30 minutes a day can make the difference between fatal heatstroke and not,” says Roberts, who recommends exercising with a buddy so you can look out for each other.Also, check on relatives, friends, or neighbors who have a difficult time leaving home and do not have air conditioning. Roberts says these people are at a higher risk of serious complications related to heatstroke and heat exhaustion since they may be stuck in a hot home. Pay attention to the way your body feels if authorities issue an extreme heat warning, and never leave people or pets in a closed car.[14]Since alcohol dehydrates the body, it’s best not to drink booze in extreme heat. “It’s important to maintain good hydration, and don’t let yourself get thirsty,” says Roberts, who says that no one-size-fits-all daily water intake is safe or helpful, as everyone needs different amounts. “Recommending a certain amount is a recipe for overhydration, which can also be dangerous. Just drink when you are thirsty, and don’t let your urine get dark yellow,” he says.TakeawayHeatstroke is more dangerous than heat exhaustion, as it can lead to organ failure and even death. However, heat exhaustion can lead to heatstroke, and people need to take caution to prevent both in extreme heat, especially if they’re very active or work in outdoor or risky industries.Treating heat exhaustion involves rapidly cooling someone down and can prevent progression to heatstroke. Heatstroke requires immediate medical attention. It can be difficult to differentiate between the two, so when in doubt do not hesitate to call 911.Additional reporting by Lisa Rapaport.