Difference between Loosen Up and Hot Up

LOOSEN UP vs HOT UP: VERB

To relax, act less seriously.
To become loose; to loosen
Cause to feel relaxed
Make one's body limber or suppler by stretching, as if to prepare for strenuous physical activity
Cause to become unblocked
Become less tense, rest, or take one's ease
Become less tense, less formal, or less restrained, and assume a friendlier manner

Fatten up, Eke out, Morning sickness, Sniff out, Unstuff, Unstrain, Unlax, Make relaxed, Limber up, Decompress, Unbend, Unwind, Relax, Slow down, Warm up

Radiomicrometer, Athermanous, Calefacient, Idiothermic, Critical temperature, Temperature, Athermic, Heat capacity, Specific heat capacity, Specific heat, Soup up, Hop up, Screw up, Heat up, Heat

Wipe away, Make headway, Body odor, Snuff out, Sit tight, Fatten up, Eke out, Morning sickness, Sniff out, Limber up, Decompress, Unbend, Relax, Slow down, Warm up

Thermotension, Refrigerative, Radiomicrometer, Athermanous, Calefacient, Idiothermic, Critical temperature, Temperature, Athermic, Heat capacity, Specific heat capacity, Specific heat, Soup up, Screw up, Heat

Your muscles really loosen up in heated water.
Great reminder to loosen up and have fun!
Do easy stretches to loosen up your muscles.
The straps can loosen up as you drive.
NEVER had one loosen up since I changed.
Turn the speakers up a little louder than you normally would will help loosen up the material.
Things are stating to loosen up as state parks and boat launches open up.
In sum, my internal workplace advice is: open up, loosen up, listen up, speak up, and don't work weekends on anything you don't enjoy.
However, they tend to loosen up after washing up for a few times.
Should I dig up and loosen up the rootball?

It's really tedious and it's really hot up there, but it's worth it.
If the valve is faulty or stuck, lines will be hot up to the valve but will cool off slightly beyond the valve.
I thought about going but it's really, really hot up there and uncomfortable and there are no toilets and you can't get a cappuccino.
This year sees the mortgage broking industry face additional pressures and responsibilities as the conversations around regulatory recommendation and review really hot up.
Vegas Golden Knights are starting to hot up at just the right time and the rest of the NHL should be on high alert.
Domestic bookings grew at a respectable 12 percent in the second quarter, but international growth was red-hot, up 44 percent from last year.
As the World Cup begins to wind down, so the cinema schedules start to hot up.
When things hot up, gono will start robbing your bank balances to finance a decaying economic system, kkkkkkkkkkkkkkkkk.
This spicy costume will be sure to hot up any Halloween celebration.
Funny, Easy Going, Hot, Up Scale, Drama Free.