to work up a sweat :
To put a great effort into doing something; to work really hard; to work so hard as is likely to make one sweat.
Explanation of the idiom used in the paragraph in context :
The writer intends to introduce the reader, somewhere further in the paragraph, to the new device scientists or researchers have designed, which could be used to produce or create power or energy using the perspiration or 'sweat' of living beings which is why they opened the paragraph with a group of words both containing the word 'sweat', and providing the meaning of working really hard as the sweat turned into energy using the invented device works for us according to the writer.
Sudoriferous: that which contains or creates sweat
Again, the writer aims to create a little fun element in the article signalling the reader to be both patient and excited to hear something special, further about 'sweat', the pivotal topic of this article, by using the words : 'hold on to your sudoriferous glands'.
Schvitzy :
Sweaty or pertaining to sweat or that which causes sweating; from Schvitz, a Yiddish (a name of a Jewish Language) term meaning 'sweat'.
Again used to make a funny reference to the topic : sweat
Their proof-of-concept setup 'Topped Out' at only 4 micro-watts:
Maximum results their experimentation of tapping the energy gained from sweat, into a battery could achieve was to produce 4 micro-watts (which was not enough even to run a watch)
to put a lid (idiom): to finally stop something bad from happening
In the article, the writer means to say that people complaining about their food poisoning disease on social media, though they don't treat it, is something that will stop diseases like food-poisoning from breaking out or starting or spreading as others will try to adopt ways to avoid such diseases in the light of their friends' food-poisoning disease experiences.
Sorry about the lengthy sentences. I am working on learning to use language concisely.
Cheers
Syed