Climate change affects health through heat, extreme weather, air quality, changing infection patterns, food and water insecurity, displacement and pressure on health services. Risk is not distributed equally: age, health, housing, work, income and local infrastructure all influence exposure and ability to adapt.
Heat and health
Heat can cause dehydration, heat exhaustion and heatstroke, and worsen heart, lung, kidney, diabetes and mental-health conditions. Heatstroke—confusion, collapse, seizures or very high body temperature—is a medical emergency.
Air, allergens and infection
Wildfire smoke and air pollution can worsen respiratory and cardiovascular disease. Longer pollen seasons may affect allergic disease. Temperature and rainfall changes can alter where some mosquito-, tick-, food- and water-borne infections occur, but local risk depends on ecology and public-health measures.
Extreme weather and mental health
Floods, storms, fires and drought can cause injury, interrupt medicines and care, damage housing and contribute to grief, anxiety or trauma. Prepared services need backup power, communication and plans for people who depend on equipment or refrigerated medicines.
Who may be more vulnerable?
- infants, older adults and pregnant people
- people with long-term illness or disability
- outdoor workers and people without safe housing
- communities with limited healthcare, water or cooling
- people taking medicines that affect hydration or temperature regulation
Practical protection
- Follow local heat, smoke and weather warnings.
- Keep medicines and emergency contacts accessible.
- Check on people who may need help.
- Use safe cooling, hydration and clean-air advice for your location.
- Seek urgent help for heatstroke, severe breathing difficulty or other emergencies.
Healthier climate action
Reducing fossil-fuel pollution, improving housing, creating shade and safe walking or cycling infrastructure, and strengthening resilient health systems can benefit health while reducing emissions.
This article provides general information. Follow current advice from local health and emergency authorities.
Sources
Last reviewed: 28 August 2026