Table of ContentsView AllTable of ContentsSunburnDehydrationHyponatremiaHeat ExhaustionHeatstroke
Table of ContentsView All
View All
Table of Contents
Sunburn
Dehydration
Hyponatremia
Heat Exhaustion
Heatstroke
Most people like to spend time outdoors onsunny days.Too much sun exposure, however, can have serious consequences. These can include:
This article looks at some of the consequences of spending too much time in the sun. It also discusses some of the ways sun-related conditions can be treated.
Science Photo Library / Getty Images
Sunburn Symptoms
Common symptoms of sunburn include:
Pain and redness tend to be greatest during the first six to 48 hours.
DermNet /CC BY-NC-ND
In severe cases, you may also have:
If these symptoms occur, contact your doctor.
Second-degree sunburnsare more serious. Symptoms include:
Hell’s Itch: How to Find Relief From Severe Sunburn Itch
When You’re at Risk
Over time, excessive sun exposure can cause long-term problems, including:Skin damagePremature skin agingSkin cancerA history of severe sunburn gives you a 2.4-fold increase in your risk ofsquamous cell carcinomaand a 1.5-fold increase in the risk ofmelanoma.
Over time, excessive sun exposure can cause long-term problems, including:
A history of severe sunburn gives you a 2.4-fold increase in your risk ofsquamous cell carcinomaand a 1.5-fold increase in the risk ofmelanoma.
Treating Sunburn
Mild sunburn can be treated at home with a cool bath or shower, cool compresses, and an over-the-counter moisturizing cream. For pain, you can take an over-the-counter pain reliever likeAdvil(ibuprofen) or Tylenol (acetaminophen). If blisters form, do not break them.
How to Treat a Sunburn
Dehydrationoccurs when your body loses too many fluids or electrolytes. This can interfere with your normal body functions. On hot days, you may become dehydrated when you’re not taking in as many fluids as you’re losing.
Symptoms of Dehydration
Most healthy people can tolerate between a 3% to 4% loss of body water without symptoms.
After 5%, you may develop:
As the water loss exceeds 10%, severe symptoms can develop, including:
Treating Dehydration
Mild dehydration will usually resolve when you drink water or an electrolyte-rich sports drink.
The best way to avoid dehydration is to drinkbeforeyou get thirsty. This is especially important if you plan to be in the sun for a long period or are overexerting yourself.
How to Prevent Dehydration
Recap
The opposite of dehydration ishyponatremia. This is sometimes also called “water intoxication.”
Dehydration isn’t just water loss. When you’re dehydrated, yourelectrolytesalso become imbalanced. Hyponatremia can occur when you lose a lot of water through sweat but you don’t replacelost sodiumwhen you rehydrate.
Hyponatremia Symptoms
Hyponatremia can happen when you lose too much sodium through sweat and replace fluids only with water. Unless you replace the lost sodium, you may experience the following symptoms:
Treating Hyponatremia
RecapDrinking too much water when you’re dehydrated can cause water intoxication. To avoid this, replace fluids with an electrolyte-rich sports drink.
Drinking too much water when you’re dehydrated can cause water intoxication. To avoid this, replace fluids with an electrolyte-rich sports drink.
Dehydration with prolonged sun or heat exposure can causeheat exhaustion. This happens when the body’s core temperature rises above 98.6° but not above 104°.It typically occurs on hot, humid days when you’re overexerting yourself.
Risk of Heat Exhaustion
Dehydration and obesity greatly increase the risk of heat exhaustion. Other factors that can contribute include:
Babies and the elderly are at greatest risk. This is because their bodies aren’t as good at adjusting to temperature changes.
Heat Exhaustion Symptoms
Common symptoms include:
Fainting From Heat Exposure
Treating Heat Exhaustion
If someone you know has heat exhaustion:
If symptoms don’t improve after 15 minutes, call 911 or seek emergency medical care. Left untreated, heat exhaustion can lead to heatstroke.
Heatstroke is also known as sunstroke. It is a more severe form of heat exhaustion. When you have heatstroke, your body’s core temperature exceeds 104°. Heatstroke causes more than 600 deaths in the United States each year.
There are two different types of heatstroke:
Causes of Heatstroke
Common risk factors for classic heatstroke include:
Death from heatstroke often occurs when younger children or the elderly are left in parked cars in direct sunlight. On a hot day, temperatures inside a parked car can quickly climb to 124° to 153°.
Heatstroke Symptoms
Symptoms of heatstroke are more profound than heat exhaustion. They can differ based on whether you have exertional or classic heatstroke. For example, sweating is typical with exertional heatstroke but not with classic heatstroke.
Other symptoms may include:
As symptoms advance, skin can suddenly take on a bluish tinge. This happens as blood vessels narrow and restrict blood flow and oxygen exchange.
Left untreated, heatstroke can lead to:
Treating Heatstroke
Heatstroke is an emergency. Treatment involves:
RecapHeat stroke is the most severe form of heat exhaustion. It can happen when you overexert yourself in hot weather or are exposed to extremely hot conditions. If you suspect heatstroke, seek medical care at once.
Heat stroke is the most severe form of heat exhaustion. It can happen when you overexert yourself in hot weather or are exposed to extremely hot conditions. If you suspect heatstroke, seek medical care at once.
Summary
Too much time in the hot sun can lead to a number of health conditions. This includes sunburn, dehydration, hyponatremia, heat exhaustion, and heatstroke.
14 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.D’Orazio J, Jarrett S, Amaro-Ortiz A, Scott T.UV radiation and the skin.Int J Mol Sci.2013;14(6):12222-48. doi:10.3390/ijms140612222MedlinePlus.Sunburn.Nemours KidsHealth.First aid: sunburn (for parents).Wu S, Cho E, Li WQ, Weinstock MA, Han J, Qureshi AA.History of severe sunburn and risk of skin cancer among women and men in 2 prospective cohort studies.Am J Epidemiol. 2016;183(9):824-33. doi:10.1093/aje/kwv282American Academy of Dermatology.How to treat sunburn.Cleveland Clinic.Hyponatremia.Lee JJ, Kilonzo K, Nistico A, Yeates K.Management of hyponatremia.CMAJ. 2014;186(8):E281-6. doi:10.1503/cmaj.120887Casa DJ, Demartini JK, Bergeron MF, et al.National Athletic Trainers' Association position statement: exertional heat illnesses.J Athl Train. 2015;50(9):986-1000. doi:10.4085/1062-6050-50.9.07National Collaborating Centre for Environmental Health.Drugs.Centers for Disease Control and Prevention.Symptoms of heat-related illnesses.Centers for Disease Control and Prevention.Extreme heat and you health.Ferrara P, Vena F, Caporale O, et al.Children left unattended in parked vehicles: a focus on recent Italian cases and a review of literature.Ital J Pediatr. 2013;39:71. doi:10.1186/1824-7288-39-71Hifumi T, Kondo Y, Shimizu K, Miyake Y.Heat stroke.J Intensive Care. 2018;6:30. doi:10.1186/s40560-018-0298-4People’s Liberation Army Professional Committee of Critical Care Medicine.Expert consensus on standardized diagnosis and treatment for heat stroke.Mil Med Res. 2016;3:1. doi:10.1186/s40779-015-0056-z
14 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.D’Orazio J, Jarrett S, Amaro-Ortiz A, Scott T.UV radiation and the skin.Int J Mol Sci.2013;14(6):12222-48. doi:10.3390/ijms140612222MedlinePlus.Sunburn.Nemours KidsHealth.First aid: sunburn (for parents).Wu S, Cho E, Li WQ, Weinstock MA, Han J, Qureshi AA.History of severe sunburn and risk of skin cancer among women and men in 2 prospective cohort studies.Am J Epidemiol. 2016;183(9):824-33. doi:10.1093/aje/kwv282American Academy of Dermatology.How to treat sunburn.Cleveland Clinic.Hyponatremia.Lee JJ, Kilonzo K, Nistico A, Yeates K.Management of hyponatremia.CMAJ. 2014;186(8):E281-6. doi:10.1503/cmaj.120887Casa DJ, Demartini JK, Bergeron MF, et al.National Athletic Trainers' Association position statement: exertional heat illnesses.J Athl Train. 2015;50(9):986-1000. doi:10.4085/1062-6050-50.9.07National Collaborating Centre for Environmental Health.Drugs.Centers for Disease Control and Prevention.Symptoms of heat-related illnesses.Centers for Disease Control and Prevention.Extreme heat and you health.Ferrara P, Vena F, Caporale O, et al.Children left unattended in parked vehicles: a focus on recent Italian cases and a review of literature.Ital J Pediatr. 2013;39:71. doi:10.1186/1824-7288-39-71Hifumi T, Kondo Y, Shimizu K, Miyake Y.Heat stroke.J Intensive Care. 2018;6:30. doi:10.1186/s40560-018-0298-4People’s Liberation Army Professional Committee of Critical Care Medicine.Expert consensus on standardized diagnosis and treatment for heat stroke.Mil Med Res. 2016;3:1. doi:10.1186/s40779-015-0056-z
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
D’Orazio J, Jarrett S, Amaro-Ortiz A, Scott T.UV radiation and the skin.Int J Mol Sci.2013;14(6):12222-48. doi:10.3390/ijms140612222MedlinePlus.Sunburn.Nemours KidsHealth.First aid: sunburn (for parents).Wu S, Cho E, Li WQ, Weinstock MA, Han J, Qureshi AA.History of severe sunburn and risk of skin cancer among women and men in 2 prospective cohort studies.Am J Epidemiol. 2016;183(9):824-33. doi:10.1093/aje/kwv282American Academy of Dermatology.How to treat sunburn.Cleveland Clinic.Hyponatremia.Lee JJ, Kilonzo K, Nistico A, Yeates K.Management of hyponatremia.CMAJ. 2014;186(8):E281-6. doi:10.1503/cmaj.120887Casa DJ, Demartini JK, Bergeron MF, et al.National Athletic Trainers' Association position statement: exertional heat illnesses.J Athl Train. 2015;50(9):986-1000. doi:10.4085/1062-6050-50.9.07National Collaborating Centre for Environmental Health.Drugs.Centers for Disease Control and Prevention.Symptoms of heat-related illnesses.Centers for Disease Control and Prevention.Extreme heat and you health.Ferrara P, Vena F, Caporale O, et al.Children left unattended in parked vehicles: a focus on recent Italian cases and a review of literature.Ital J Pediatr. 2013;39:71. doi:10.1186/1824-7288-39-71Hifumi T, Kondo Y, Shimizu K, Miyake Y.Heat stroke.J Intensive Care. 2018;6:30. doi:10.1186/s40560-018-0298-4People’s Liberation Army Professional Committee of Critical Care Medicine.Expert consensus on standardized diagnosis and treatment for heat stroke.Mil Med Res. 2016;3:1. doi:10.1186/s40779-015-0056-z
D’Orazio J, Jarrett S, Amaro-Ortiz A, Scott T.UV radiation and the skin.Int J Mol Sci.2013;14(6):12222-48. doi:10.3390/ijms140612222
MedlinePlus.Sunburn.
Nemours KidsHealth.First aid: sunburn (for parents).
Wu S, Cho E, Li WQ, Weinstock MA, Han J, Qureshi AA.History of severe sunburn and risk of skin cancer among women and men in 2 prospective cohort studies.Am J Epidemiol. 2016;183(9):824-33. doi:10.1093/aje/kwv282
American Academy of Dermatology.How to treat sunburn.
Cleveland Clinic.Hyponatremia.
Lee JJ, Kilonzo K, Nistico A, Yeates K.Management of hyponatremia.CMAJ. 2014;186(8):E281-6. doi:10.1503/cmaj.120887
Casa DJ, Demartini JK, Bergeron MF, et al.National Athletic Trainers' Association position statement: exertional heat illnesses.J Athl Train. 2015;50(9):986-1000. doi:10.4085/1062-6050-50.9.07
National Collaborating Centre for Environmental Health.Drugs.
Centers for Disease Control and Prevention.Symptoms of heat-related illnesses.
Centers for Disease Control and Prevention.Extreme heat and you health.
Ferrara P, Vena F, Caporale O, et al.Children left unattended in parked vehicles: a focus on recent Italian cases and a review of literature.Ital J Pediatr. 2013;39:71. doi:10.1186/1824-7288-39-71
Hifumi T, Kondo Y, Shimizu K, Miyake Y.Heat stroke.J Intensive Care. 2018;6:30. doi:10.1186/s40560-018-0298-4
People’s Liberation Army Professional Committee of Critical Care Medicine.Expert consensus on standardized diagnosis and treatment for heat stroke.Mil Med Res. 2016;3:1. doi:10.1186/s40779-015-0056-z
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