Online Dermatologist > How Heatwaves Affect Your Skin

Why Heatwaves Stress Your Skin

Heatwaves place significant stress on your skin, which acts as your body’s primary interface with the environment and plays a critical role in regulating your internal temperature. During periods of extreme heat, a combination of elevated temperatures, increased UV radiation, and environmental factors can compromise your skin’s health.

Heat rash (miliaria) under the arm, showing red inflamed patches caused by trapped sweat during hot weather.

Here’s how heatwaves impact your skin.

• Increased Bodily Responses: Hot weather naturally increases sweating, oil production, and blood vessel dilation. While sweating is essential for cooling the body through evaporation, excessive sweat, especially when trapped, can clog pores. This leads to issues like heat rash, as the epidermis thickens and struggles to eliminate toxins and sebum.
• Weakened Skin Barrier: The combined assault of high temperatures, intense UV radiation, and air pollution can significantly weaken the skin’s protective barrier. This makes the skin more vulnerable to external irritants and can lead to increased dryness and fragility. Aggressive UVA rays, in particular, penetrate deep into the dermis, contributing to premature skin aging (photo-aging).
• Moisture and Microbial Growth: Humid and moist environments, particularly in skin folds or areas covered by clothing, create ideal breeding grounds for fungi and bacteria. This can lead to various infections and skin irritations.
• Exacerbation of Existing Conditions: Many pre-existing skin conditions are prone to flare-ups during heatwaves. Conditions such as eczema, rosacea, and acne can worsen due to increased inflammation, dehydration, or heightened photosensitivity.

Who’s Most at Risk During a Heatwave?

While everyone can be affected by extreme heat, certain groups are particularly vulnerable to the skin-related impacts of heatwaves and the broader risks of heat-related illness. Understanding these vulnerabilities can help ensure targeted protection.

Here are the groups most susceptible to skin stress during a heatwave

• Infants and Young Children: Their sweat glands are not yet fully developed, making them more prone to heat rash and eczema. They are also easily dehydrated and have a higher risk of sunburn due to their delicate skin.
• Elderly Adults: As we age, skin elasticity and the ability to sweat naturally decrease. This can lead to a higher risk of dryness, skin ulcers, and sun damage. Older adults may also experience worsening of chronic skin conditions and increased susceptibility to issues like actinic reticuloid.
• Individuals with Pre-existing Skin Conditions: People living with conditions such as eczema, rosacea, acne, and psoriasis often find their symptoms worsen during hot weather due to increased sweat, inflammation, dehydration, or heightened photosensitivity.
• Pregnant Individuals: Hormonal changes during pregnancy, combined with heat, can increase sensitivity, leading to conditions like melasma (dark patches on the skin) and general redness.
• Outdoor Workers & Athletes: Individuals who spend extended periods outdoors are at higher risk of sunburn, folliculitis (inflammation of hair follicles), heat rash, and fungal infections. This is due to prolonged exposure to sun, sweat, and friction.
• Other Vulnerable Populations: Beyond age and physiological factors, social determinants of health—such as geography, socioeconomic status, and access to medical care—can also increase the burden of skin diseases during extreme weather events, particularly affecting marginalized communities.

During heatwaves, increased time spent outdoors, often with less protective clothing, can heighten exposure to UV radiation and air pollution, further increasing risks like sunburn and various photodermatoses.

Common Skin Conditions That Flare During Heatwaves

Extreme heat and humidity create an environment conducive to the development or exacerbation of numerous skin conditions.

How Heat and Pollution Combine to Harm Your Skin

During heatwaves, not only do temperatures soar, but the concentration of air pollutants, such as ground-level ozone and fine particulate matter, often rises. This combination creates a particularly challenging environment for your skin.

When skin is exposed to both heat and pollution, it undergoes increased oxidative stress. This process generates unstable molecules that can damage skin cells, accelerating the breakdown of collagen and elastin, which are vital for skin elasticity and firmness. Over time, this can speed up the visible signs of aging.

The immediate effects on your skin may include a dull appearance, increased redness, irritation, and even breakouts. Existing conditions like rosacea, eczema, and acne can also be significantly worsened by this environmental assault.

To mitigate these effects, cleanse your face and body thoroughly after any outdoor exposure. Incorporating antioxidant-rich products, such as Vitamin C serums, into your morning skincare routine can help neutralize free radicals caused by pollution.

Skincare Tips to Protect Your Skin in Hot Weather

Protecting your skin during heatwaves requires a comprehensive approach that goes beyond just sunscreen. By adopting a few key strategies, you can minimize discomfort and prevent heat-related skin issues.

Stay Cool & Seek Shade

• Minimize Exposure: Limit your time outdoors during the hottest parts of the day, typically between 11 AM and 3 PM.
• Seek Cooler Environments: Spend as much time as possible in air-conditioned indoor locations. If AC isn’t available, use fans or take cool (not cold) showers or baths to help lower your body temperature.
• Limit Strenuous Activity: Reduce physical exertion during peak heat to prevent excessive sweating and overheating.

Hydrate Inside and Out

• Drink Plenty of Fluids: Stay well-hydrated by drinking ample water throughout the day, even if you don’t feel thirsty, to compensate for fluid loss through perspiration. Water-rich foods like cucumber and watermelon can also contribute to hydration. Avoid excessive caffeine and alcohol, which can lead to dehydration.
• Moisturize Lightly: Apply light, non-comedogenic moisturizers, preferably those containing hydrating ingredients like hyaluronic acid or glycerin, to your skin every morning and evening, especially after bathing.

Practice Smart Sun Protection

• Apply Sunscreen Diligently: Use a broad-spectrum mineral sunscreen with an SPF of 30 or higher. Apply generously to all exposed skin at least 15 minutes before going outdoors and reapply every two hours, or more frequently if swimming or sweating. Look for sunscreens with at least 4 UVA stars or the UVA circle symbol for robust protection.
• Wear Protective Clothing: Opt for UV-protective clothing, wide-brimmed hats, and sunglasses to provide a physical barrier against the sun’s rays.
• Don’t Rely Solely on Sunscreen: Even with sunscreen, it’s beneficial to seek shade, as UV rays can still cause damage.
• Rethink Vitamin D from Sun: The British Association of Dermatologists advises against sunbathing for Vitamin D, especially during heatwaves, as the skin receives damaging UV rays long after optimal Vitamin D levels are reached. Consider fortified foods or supplements as safer alternatives.

Choose Appropriate Clothing

• Favor Loose, Breathable Fabrics: Select loose-fitting, lightweight, and light-colored clothing made from natural fabrics like cotton or linen. These materials allow air circulation, promote cooling, and prevent heat from being trapped against the skin, reducing sweating and friction.

Maintain Gentle Skin Hygiene

• Cleanse Thoroughly: Wash your face and body with mild, non-irritating cleansers after outdoor exposure and sweating. This helps remove pollutants, sweat, and excess oil that can clog pores.
• Avoid Harsh Products: Refrain from over-scrubbing or using harsh exfoliants on irritated skin, as this can worsen existing conditions.
• Manage Excess Oil: Use mattifying skincare products or gentle wipes to manage excess sweat and sebum production, which can otherwise lead to clogged pores and breakouts.
• Dry Skin Folds: After bathing, thoroughly pat dry all skin folds to prevent moisture buildup, which can promote fungal and bacterial growth.

Overall Heat Safety

• General Safety Measures: Always prioritize general heat safety during extremely high temperatures. Stay in air-conditioned environments, check on vulnerable friends and neighbors, and never leave children or pets in parked cars, even for a short time.

When to Contact a Dermatologist

While many heat-related skin issues can be managed with home care, it’s crucial to know when to seek professional medical advice. You should promptly consult a board-certified dermatologist if you notice rashes that are spreading, oozing, or blistering. Similarly, if chronic conditions like eczema or acne experience flare-ups that do not improve with your usual home remedies, professional intervention may be needed. Signs of a skin infection, such as increasing redness, swelling, warmth, pain, pus, or an accompanying fever, warrant immediate attention.

For severe sunburns that present with extensive peeling, fever, or chills, a medical evaluation is recommended. Additionally, any new or changing dark spots on your skin, especially after extended sun exposure, should be examined by a dermatologist to rule out more serious concerns. For convenient access to expert care, online platform First Derm™ offers access to board-certified dermatologists 24/7, without the need for appointments or referrals.

Frequently Asked Questions

How can I tell if my baby has heat rash or an allergic reaction during hot weather?

Heat rash (miliaria) typically presents as small red or clear bumps on areas covered by clothing, such as the neck, back, or underarms. Your baby might seem irritable or fussy but otherwise well. Conversely, allergic reactions often involve hives (raised, blotchy welts), swelling, or a sudden onset after exposure to a new food, fabric, or product. If the rash spreads rapidly, causes significant swelling, or is accompanied by difficulty breathing or vomiting, seek immediate medical attention.

What is the safest way to keep my newborn cool and rash-free during a heatwave?

To keep your newborn safe and comfortable during extreme heat, ensure they are in a well-ventilated or air-conditioned room. Dress them in a single layer of loose, breathable cotton clothing and avoid swaddling, which can trap heat. Use a fan positioned to circulate air without blowing directly on the baby. Frequent, short, lukewarm sponge baths can also help regulate their body temperature. Avoid using thick creams that might block sweat glands, and always ensure skin folds are kept dry. Crucially, never leave babies in parked cars or any sun-exposed areas, even for brief periods.

Can a baby get sunburn just from sitting in the shade on a hot day?

Yes, babies can indeed get sunburned even when in the shade, as harmful UV rays can reflect off surfaces like sand, concrete, and water. For babies under six months, it is essential to keep them out of direct sunlight entirely. Dress your baby in wide-brimmed hats and protective clothing, and utilize a stroller shade or umbrella for added protection. For babies over six months, apply a mineral-based sunscreen containing zinc oxide or titanium dioxide to all exposed skin areas.

Why does my elderly mother’s skin peel and turn red when it’s hot outside?

As individuals age, their skin naturally becomes thinner, drier, and more sensitive to environmental factors like heat. During hot weather, increased sweating combined with friction from clothing can lead to redness, irritation, and peeling, which can sometimes be mistaken for sunburn or eczema. Heat can also worsen pre-existing skin conditions such as dry skin or rosacea. To help prevent these flare-ups, encourage regular moisturizing, ensure she wears loose and breathable clothing, and help her stay in cool environments.

How can I stop getting fungal infections in my groin area during summer work shifts?

To prevent fungal infections in skin folds during hot, sweaty conditions, wear loose, moisture-wicking underwear made from breathable fabrics like cotton. Change out of sweaty clothes as soon as possible and shower daily with a gentle cleanser. After bathing, thoroughly pat dry all skin, especially in folds. Applying antifungal powder or barrier creams to reduce friction and moisture buildup can also be beneficial. If symptoms such as persistent itching, redness, odor, or rash do not improve, consult a dermatologist. You may consider leveraging online platforms for quick access to specialists to rule out fungal or bacterial infection.