It's been so hot lately I feel dazed and lethargic from the heat.
My energy levels are zapped from all the hot weather we've had lately and I feel spaced out on top of that.
この場合、次のような言い方ができますよ。
ーIt's been so hot lately I feel dazed and lethargic from the heat.
「最近すごく暑くて、熱で頭がぼんやりしてだるい」
to feel dazed「ぼんやりする」
lethargic「だるい・無気力な」
ーMy energy levels are zapped from all the hot weather we've had lately and I feel spaced out on top of that.
「最近のこの暑い天気で気力がないし、その上、頭もぼんやりする」
my energy levels are zapped「元気が消耗された」
to feel spaced out で「ぼんやりする」
ご参考まで！
カナダ 
