ツバメ1羽来ただけで夏にはならない。
Please be careful not to get sick from the summer heat.
I can not pass the summer without a mosquito-net.
Let's take precautions against heat fatigue, before we flake out from the heat, and have a healthy summer.
Even books get mildewed in the rainy season.
Swallows fly away at the approach of winter.
In summer, bread grows mouldy―becomes covered with mould―shoes and clothes get mildewed―become covered with mildew.
“Beggars should not be choosers”【イディオム・格言的】