Summer destroys my sleep every single year. This year I finally fixed it.

Every summer the same cycle. May hits, temperatures climb, my bedroom becomes a sauna by midnight even with AC, and my sleep quality tanks for 4 months straight. Last summer I tracked it. June through September my average deep sleep dropped from 68 minutes to 39. Wake-ups went from 1.5 per night to 4.2. My Whoop recovery scores were consistently yellow and red. By August I was exhausted, irritable, and my work was suffering. This year I attacked it systematically. First, I realized my AC was cooling the air but not the surface I was sleeping on. My foam mattress was absorbing heat all day from the warm room and then slowly releasing it at night. Even with AC running, the mattress surface stayed warm. I replaced it with one where the structure lets air move through the core instead of trapping heat in dense foam. The surface stays closer to room temperature now. Second, I switched from a thick cotton bedsheet to a thin bamboo one. Bamboo wicks moisture better and feels cooler against skin. Third, I set the AC to 19 degrees at 9pm and let it cool the room and mattress for 2 hours before I get in at 11. Fourth, no dinner after 8pm. Digestion raises core body temperature and I was eating at 10pm then wondering why I was hot in bed. This summer my deep sleep stayed between 55 and 65 minutes through June and July. Wake-ups averaged 1.8. I felt like a different person. The biggest lever was the mattress. Everything else helped but the heat trap I was sleeping on was the root cause. Cool the surface, not just the air.