The first really warm day in May

Short answer: The body is not used to the warmth yet, and most people are dressed too warm. Switch to thin underwear and a single layer, and keep the thick jumper in your bag.

The body needs to adjust

The first warm day feels warmer than the same temperature in August, because the body has not yet adapted to sweating efficiently. That adaptation happens gradually over weeks, not from one day to the next, so you sweat more now than you will later in summer. See bamboo clothing for women.

Underwear changes first

Switch to thin underwear before you switch the outer layer. That is where the difference is felt most, because it sits closest to the skin and has the biggest effect on how warm you feel through the whole day. See bamboo underwear for women.

Evenings still turn cold

In May temperature often drops ten degrees or more after sunset, even on a day that has felt spring warm all afternoon. A layer in the bag is therefore necessary, no matter how warm it was at midday.

Socks are noticed straight away

Thick winter socks at twenty five degrees are felt within an hour. Change them early in the day, along with underwear, rather than waiting until feet have already become uncomfortably warm. See bamboo socks for women.

Sun behind glass tricks the thermometer

A room or a car that has stood in the sun can feel far warmer than the outdoor temperature shows, because glass lets heat in without letting it back out. Dress for the weather outside, not for the feeling in the car on the way there.

Too many layers in the morning

Many people keep the morning's layers all day, even once temperature has risen noticeably. Check the thermometer at midday and be willing to remove a layer, rather than automatically sticking with what you started in.

T-shirt at lunch, jacket again by evening

A simple rule for May is to wear a t-shirt at lunch if the sun is out, and bring the jacket back once shadows grow longer. See bamboo t-shirt for women.

Fluids are easily forgotten on the first warm day

Because the body is not used to the heat, many forget to drink enough on the first truly warm day. The symptoms can easily be mistaken for simply being tired after a long day outdoors.

Shade feels like a different season

In direct sun May can feel like summer, while shade in the same spot still feels like early spring. Choose clothing that works in both, rather than dressing only for the sunny side of the street.

Frequently asked questions

Why does the first warm day feel warmer?

Because the body is not yet adapted. Adjusting to sweat efficiently takes two to three weeks, so you sweat more now than later at the same temperature.