Eight Sleep launches early Black Friday deal with $200 off Pod 6 smart mattress cover

Eight Sleep has cut the price of its Pod 6 smart mattress cover by up to $200 in an early Black Friday promotion. The device uses water-filled tubes to heat or cool the bed during sleep, and the offer is available in the United States and the United Kingdom. The reviewer says the cover may suit people who overheat at night, while noting that a subscription is required.