German tenants are being urged to strengthen heat protection as both winter drafts and summer overheating can harm health and raise costs. Recommendations include checking window seals, adding effective curtains or blinds, improving ventilation schedules, and ensuring thermostats and radiators work properly. Tenant associations also call for faster landlord action on insulation and shading, especially in older buildings. During heatwaves, residents are advised to ventilate early, keep curtains closed during peak sun, and monitor indoor temperatures to prevent heat stress.