When the Heat Won't Let You Rest: Summer, Sleep, and Your Mental Health

When the Heat Won't Let You Sleep (and Why It Affects Your Mood, Too)

If you've spent a summer night tossing and turning, then woke up groggy and irritable, you're not imagining it. Heat really does mess with your sleep, and bad sleep really does affect your mood. The good news is there's a lot you can do about it.

Why heat gets in the way of sleep

Falling asleep depends on your body cooling down slightly, by about 2°F. This happens naturally starting a couple hours before bedtime, around the same time your body releases melatonin, the hormone that signals it's time to wind down. When your bedroom is too warm, that cooling process gets interrupted. Instead of deep, restorative sleep, you end up in lighter, more restless sleep, the kind that leaves you tired even after a full night in bed. Aim for a bedroom between 60 and 67°F for the best results.

Why this matters for your mood

Sleep and mood are closely connected. When sleep suffers, especially over several nights in a row, it's common to feel more irritable, anxious, or low. Summer heat can also affect mood more directly, not just through sleep loss. So if you've noticed summer feels a little heavier or harder than other seasons, the heat itself may be part of the reason, on more than one front.

What helps

A few simple habits go a long way:

• Go to bed and wake up at the same time every day

• Keep your bedroom cool, quiet, and relaxing

• Turn off screens at least 30 minutes before bed

• Avoid caffeine and alcohol in the evening

• Use lighter bedding and breathable sleepwear in summer

• Run a fan or air conditioning, and use blackout curtains to keep daytime heat out of your room