Gas stoves burn natural gas, which releases nitrogen dioxide and other compounds that irritate the lungs, and more than one-third of American households cook with them. In a small study of 85 adults and children with poorly controlled asthma, contractors replaced gas stoves with electric induction stoves at no cost. Over two to three months, average symptoms went from moderate to mild, emergency visits and hospitalisations for asthma fell by 70%, and missed days of work or school dropped by about 80%. Indoor nitrogen dioxide levels fell by 70%. Induction stoves heat and cool quickly and are easier to clean than coil stoves. Participants were far more satisfied, with 98% happy with the electric stove compared with 41% with gas. The study was small and had no comparison group, so its results need larger trials.

Hampi is a UNESCO World Heritage Site in Karnataka, India, with more than 1,600 surviving remains spread over 4,100 hectares. It was the capital of the Vijayanagara Empire from 1336 to 1565. Travellers from Persia and Portugal described it as a prosperous, wealthy and grand city with temples, markets and farms along the Tungabhadra River. By 1500 it was estimated to be the world's second-largest city after Beijing, and probably India's richest at the time. In 1565 a coalition of Muslim sultanates defeated the Vijayanagara Empire, its capital was conquered and destroyed, and the city was left in ruins. Hampi remains a religious centre, with the active Virupaksha Temple at its heart.