14 Sun Poisoning Symptoms

2. Blistering and Peeling of the Skin

Blistering is a clear sign of severe sun damage. After intense sun exposure, the skin may become red and swollen as it reacts to the injury. Small or large fluid-filled bubbles form to protect the tissue underneath, and these blisters can feel tight, painful, and very sensitive to touch.

Blisters may break open on their own. When this happens, the raw skin underneath feels tender and may sting. Open blisters also increase the risk of infection if the area is not kept clean. A few days later, peeling begins as the body sheds damaged skin and replaces it with new tissue.

Large sheets or small flakes of skin may come off during this stage. Peeling can cause itching and dryness, and scratching may further irritate the skin or slow healing. Areas that blister often remain more sensitive to heat, water, or friction until the new surface layer fully forms.

3. Swelling of the Skin

Swelling of the skin is a common sign of sun poisoning. Ultraviolet light from strong sun exposure damages skin cells, prompting the body to send extra blood and fluid to the affected area. This causes the skin to look puffy, raised, or stretched and to feel tight and tender to the touch.

The swollen area may feel warm or hot. In some cases, the skin becomes red and painful. People with lighter skin tones may notice clear redness, while those with darker skin tones may notice puffiness and tenderness without much color change. Swelling can affect small patches or larger areas, such as the shoulders, back, or legs.

Severe cases may include fluid-filled blisters, which increase the sensation of tightness and discomfort. The skin may feel firm when pressed, sometimes leaving a small dent that disappears after a few seconds. Other symptoms can appear along with swelling, including itching, burning, or mild fever.

4. Dehydration

Dehydration happens when the body loses more fluids than it takes in. In strong sun and high heat, sweat loss rises quickly, and if these fluids are not replaced, the body cannot cool itself effectively. Early signs often include thirst, dry mouth, dark yellow urine, and reduced urination. Headaches, tiredness, or dizziness may also appear.

As fluid loss continues, the skin may feel dry, the pulse can become faster, and breathing may speed up. Some people feel lightheaded when standing. Children and older adults face higher risk. People taking certain medications, such as diuretics or some blood pressure medicines, and those spending long periods outdoors without shade may lose fluids more quickly. If dehydration progresses, confusion and poor focus can develop.

In severe cases, a person may faint or show signs of heat exhaustion. Quick replacement of fluids helps prevent more serious heat-related illnesses. Muscle cramps may also develop when sweating causes the body to lose both water and electrolytes.

5. A Headache

A headache is a common sign of sun poisoning. It often starts after long hours in strong sunlight, with pain that may feel dull at first and then become steady or throbbing. Sun poisoning can lead to dehydration, and fluid loss can cause the brain to react with pain.

Heat and direct sun exposure also strain blood vessels in the head, which can trigger or intensify discomfort. The headache may affect one side of the head or both. Some people describe it as pressure, while others feel pulsing pain. Bright light can make the pain worse, especially if the eyes are already irritated from sun glare.

Children and older adults may show fewer clear signs, but they can still develop a strong headache.In more serious cases, the headache can last for several hours or even a full day and may be accompanied by weakness, confusion, vomiting, vision changes, or fainting.

6. A Fever

A fever is a rise in body temperature above the normal range of about 98.6°F (37°C). In cases of sun poisoning, it can develop after long and intense sun exposure. Sun poisoning is a severe form of sunburn that inflames the skin, and the body reacts as if it is fighting an illness, which can raise body temperature.

A person with a fever may feel hot, tired, or chilled. They might sweat more than usual, feel weak or shaky, and experience headaches, body aches, nausea, or dizziness. Fever often appears along with red, blistered skin that feels warm or painful to the touch.

Children, older adults, and people who stay in the sun for many hours face a higher risk. Dehydration can make the fever worse because the body struggles to cool itself. Doctors may suggest rest, fluids, and over-the-counter pain relievers.

7. Chills and Shivering

Chills and shivering can appear when sun poisoning becomes severe. The body may feel cold even though the skin feels hot to the touch, which can be confusing. Shivering happens as the body tries to control its internal temperature. Sun poisoning can raise core body temperature, and when this process breaks down, the body may trigger muscle shaking in response to stress.

Chills can also signal dehydration or a more serious heat-related illness. Heavy sweating, dizziness, nausea, and weakness may appear at the same time. If the skin turns very red and painful from intense sun exposure, chills may follow as the body struggles to recover.

Children, older adults, people with chronic health conditions, and those taking certain medications, such as diuretics or drugs that affect temperature control, face higher risk of heat-related complications. A mild fever may also occur as the body reacts to widespread skin inflammation after prolonged ultraviolet exposure.

8. Feelings of Dizziness and Lightheadedness

Dizziness and lightheadedness often appear when the body reacts to severe sun poisoning. A person may feel faint, weak, or unsteady, sometimes as if they might pass out. Lightheadedness differs from vertigo because it usually feels like imbalance or near-fainting rather than a spinning sensation.

These feelings can start suddenly and may follow nausea, vomiting, sweating, or headache. Fluid loss through vomiting or diarrhea can cause blood pressure to drop, reducing blood flow to the brain and triggering dizziness. In more serious cases, dizziness may occur alongside a slow pulse, low blood pressure, or confusion, making it difficult to stay alert.

Children, older adults, and people who are already dehydrated may experience these symptoms more strongly. The intensity can range from mild unsteadiness to brief loss of consciousness. Standing up quickly after sitting or lying down may make the sensation more noticeable when fluid levels are already low.

9. Nausea

Nausea is a common symptom of sun poisoning. It makes a person feel sick to their stomach, as if they might vomit, and can start a few hours after heavy sun exposure. Sun poisoning often follows a severe sunburn. The body reacts to skin damage and inflammation, and this stress response can upset the stomach, leading to nausea.

A person may also feel weak, dizzy, or lightheaded. Heat exposure lowers fluid levels in the body, and dehydration can make nausea worse. Vomiting can increase fluid loss, creating a cycle where dehydration and nausea feed into each other. Children and older adults may show symptoms faster than healthy adults.

In some cases, nausea signals a more serious reaction to heat and sun. The body may struggle to cool itself, especially after long hours outdoors without shade or water. When nausea lasts more than a day or occurs with confusion, high fever, or severe weakness, it may indicate a deeper heat-related illness rather than a simple sunburn.

10. A Tingling Sensation

A tingling sensation can be an early sign of bitter sun poisoning. A person may feel pins and needles in the fingers, toes, lips, or face, and this feeling can slowly spread to other parts of the body.

The sensation often starts mild, feeling like the skin is lightly buzzing or prickling, and over time it can become stronger and harder to ignore. Certain toxins affect the nerves, causing them to send mixed or weak signals to the brain, which results in unusual skin sensations even without touch.

In some cases, tingling appears before muscle weakness; in others, it occurs at the same time. If the toxin continues to affect the nerves, tingling can turn into numbness. The skin may feel less sensitive to touch or temperature, making simple tasks like holding objects or walking feel harder than usual.

11. Fainting

Fainting is a brief loss of consciousness caused by reduced blood flow to the brain. In cases of sun poisoning, heat, dehydration, or long periods in direct sunlight can trigger fainting. Standing too long in the sun or rising too quickly from a seated position can make it more likely.

Heat causes blood vessels to widen, lowering blood pressure and reducing blood flow to the brain, which leads to a brief loss of consciousness. The skin may look pale, and muscle tone may weaken. Most episodes last less than a few minutes, and the person usually wakes up quickly.

Certain medications, such as blood pressure drugs, diuretics, or some mental health medications, as well as alcohol use and low blood sugar, can increase the risk. Fainting linked to sun exposure may signal heat exhaustion or another heat-related illness. If the person does not wake within a few minutes, has chest pain, trouble breathing, or shows confusion after waking, urgent care is needed.

12. Swollen Lips

Swollen lips can appear after long hours in a strong sun. The lips have thin skin and little natural protection, which makes them easy to burn. Sunburn on the lips may cause puffiness, redness, and pain.

The area can feel tight or tender, and in some cases, small blisters may form. Swelling can also happen as part of a wider reaction to sun exposure, when the body releases chemicals that cause fluid to build up in soft tissue. Cold, dry, or windy weather and dehydration can make the problem worse by adding to dryness and irritation.

Severe swelling needs prompt attention, especially if it comes with trouble breathing, dizziness, or hives, as these signs may indicate a serious reaction affecting more than just the skin. Repeated sun damage to the lips can lead to rough, scaly patches that may feel dry and sandpaper-like.

13. Itching

Itching is a common sign of sun poisoning. Strong ultraviolet light damages the skin and triggers sun poisoning. The body reacts to this damage with inflammation, which can cause redness, swelling, rash, and itching. The skin may feel irritated, prickly, or as if something is crawling on it.

Itching may start within a few hours of sun exposure and can become more intense over the next day. Skin that already feels tight or dry from a burn often itches more. Repeated scratching can break the skin, raising the risk of infection and slowing healing.

Severe itching can also disturb sleep. When itching lasts for several days or spreads beyond the sunburned area, it may signal a stronger reaction to sun exposure. Peeling skin often becomes itchier as the damaged outer layer begins to loosen during healing. Warm showers or friction from clothing may also make the itching feel more noticeable while the skin remains sensitive.

14. Weakness

Weakness is a common sign of sun poisoning. A person may feel drained, shaky, or unable to carry out normal tasks. Even simple movements, such as standing up or walking across a room, can feel harder than usual. Sun poisoning often causes fluid loss through heavy sweating.

When the body loses too much water and salt, muscles do not work as well, leading to low energy and a feeling of heaviness in the arms and legs. Some people may also feel lightheaded along with weakness. If weakness lasts more than an hour, worsens, or occurs with confusion or trouble breathing, it may signal a more serious heat-related illness.

The body may struggle to cool itself, which can affect blood flow and muscle strength. Children, older adults, and people taking certain medications, such as diuretics or blood pressure drugs, may face a higher risk, as their bodies can lose fluids faster or have trouble maintaining a stable temperature.