Historical clue formulations

• Server's warning at a restaurant — 2026-09-18
• Remark while fanning oneself, maybe — 2025-01-14
• Line around the Equator? — 2024-05-11
• Summer complaint — 2020-03-29
• Sweater's line? — 2013-10-13
• "Boy, am I shvitzing!" — 2010-05-23
• Summer complaint — 2005-02-13