Perfect conditions mean that you aren't in water or sweating, two things that usually go hand in hand with the sun.

理想的条件意味着你不是在水里或出汗。 而这两个事情通常和阳光密切联系在一起。

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A sweating, bespectacled farmer who was standing behind the camera said that all the snakes had come out of the water and climbed into the trees.

一位站在摄像头背后，汗流浃背，带着眼镜的农民说，所有的蛇都浮出水面爬到树上。

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Sweating cools the body down, but if you lose too much water this way, you could get dehydrated.

流汗使您的身体降温，但是如果您失去太多的水份，您可能会脱水。

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Half were randomly to be instructed to apply the sunscreen daily to exposed areas, reapplying after water immersion, heavy sweating or several hours spent outdoors, while half were told to use it as they normally would.

WSJ: Sunscreen Each Day Stops Wrinkles

Forecasters say people should limit outdoor activity during the hottest portions of the day, wear lightweight clothing, drink plenty of water and be watchful for signs of heat exhaustion, which include heavy sweating, pale and clammy skin, weak pulse, fainting and vomiting.

CNN: Heat advisories issued to states dwindles to 15

The new rules also say that products claiming water resistance must say how long a user can expect to get that protection while swimming or sweating, either 40 minutes or 80 minutes.

WSJ: Sunscreen Each Day Stops Wrinkles