Winston Churchill’s one-man pressure chamber, used on his personal plane during WWII. It had ash trays, a telephone and an air-circulation system.

Winston Churchill was susceptible to pneumonia and the long cold flights weren’t good for his health (none of Churchill’s planes were pressurized). He would wear an oxygen mask on some occasions (even when he slept). Sometime in 1942 they did build a pressure chamber for him, but they couldn’t get it into his plane without dissembling the tail section. The contraption was rejected out of hand – thus never used.

(Source)