Good God, it's hot! National weather maps show that two-thirds of the U.S. is living under oppressive (90+ degrees) heat this week, and for some of those states, early June is early for enduring this kind of heat. Every year, usually in July, I publish another round of "warm weather care" tips for guinea pigs, but this heat wave moved up the schedule. This weather is the kind of weather in which outdoor livestock needs to be brought into shade with unlimited water, and domestic animals need to be inside with air conditioners running. Not just lots of fans running with all the shades drawn. Air conditioning.

Below are 8 tried-and-true suggestions for summer care. For those who have menageries of pets that include some combination of guinea pigs, rabbits, cats, dogs, hamsters, ferrets, birds, and more, several of these suggestions have applicability to your entire brood.

Maintain Comfortable Room Temperatures

Guinea pigs' ideal temperature range is 65 to 75 degrees Fahrenheit (remember, the species originated in the cool mountain regions of South America). Personal observation of middle-aged and senior pigs has repeatedly shown that this range caps at about 72 degrees. The farther the thermometer climbs past 75 degrees, the greater the likelihood that a guinea pig will suffer from heat stress, heat exhaustion, and (usually fatal) heatstroke. These conditions kick in quickly, and can take a guinea pig down quickly. With all the small exotics, little bodies mean little time to conquer a dangerous illness.

Cool, climate-controlled rooms provide maximum comfort for your critters and peace of mind for you. Using window blinds to diffuse the incoming sunlight, or block it on extremely hot days, can help maintain a room's climate.

Re-evaluate The Cage's Location

Move the guinea pig cage into a different room where you know your pigs will be cool enough. This might be a room in a shady corner of the house or one that catches a steady breeze, or it might be a room with an air conditioner in it. This way, you can close the door, set the air conditioner on low (so the room doesn't turn into a freezer), and keep your electricity bill manageable.

Remember that even in warm weather, guinea pigs can get sick from drafts. Avoid opening windows that are right next to their cage, leaving a fan (even an oscillating fan) going that can blow air directly into their cage, or putting them directly in line with the blast of air conditioner air. You can open windows in another part of the same room, or position the fan so that it will cool the room without blowing on your pigs. If the cage is right next to a window that gets a lot of sun, closing the shades, adjusting the direction of the Venetian blinds, or closing the curtains can filter out the sunlight (and the resulting heat) from their cage. Moving the cage away from the window entirely is the most worry-free solution.

Putting the cage outside -- even in a shady location -- is NEVER an option.

Ignore Attempts to Qualify

I know there are people and care guides out there that try to put qualifiers on guinea pigs' temperature sensitivities, such as "Guinea pigs can't tolerate high temperatures unless XYZ is in place." My experience with animal rescue, and my experience as a technical writer (a career spent writing guides that people only grudgingly read), tells me it's a risky gamble to assume that people are going to remember all the if/then/however qualifiers. I'm not being pessimistic. At the rescue for which I volunteer, we have seen and heard too much over the years. We know that the 65-75 degree range has helped keep a lot of guinea pigs out of trouble, and we stand by the species' innate, genetic tolerances.

Take Pet Lethargy Seriously

I've been in people's houses on 85+ degree days, with no air conditioning on, where the homeowners said their animals "do fine" in heat waves with the household's window fans, ceiling fans, attic fan, all shades and curtains drawn, and so on and so on. "Do fine" is relative. The pets might not have been showing signs of heatstroke, but their quality of life was debatable. Lying around all day, lethargy apparent in every step they took to their food and water, not visiting their water nearly as much as they should have been because they were too hot to move. Their owners chattered on, saying things like, "The pets come back to life when the sun goes down" -- and seemed oblivious to the volumes that the observation spoke.

Hydrate, Hydrate, Hydrate

Before you leave the house in the morning, make sure the water bottle is full and that water comes out of the drinking spout when you touch the metal ball at the tip. This metal ball bearing can sometimes get stuck, preventing water from coming out properly or at all. If the metal ball isn't working (right), a good shake or two will usually fix the problem.

On days when you have to run in for dinner and then run back out for a few hours in the evening, check the water bottle's level before you go back out. If they drank a lot during the day, they may have little water left by the time you get home...and won't have enough to make it through the hours you're gone in the evening. Depending on how warm the day gets, your guinea pig(s) could drink a full bottle of water in the 8-ish hours you're at work.

You also want your water bottle to be big enough for the number of guinea pigs you have. Don't rule out buying a bigger bottle or a second bottle. In fact, if you have three or more pigs in a cage, having two bottles (as a general rule) is a great idea. In every colony, there always seems to be one guinea pig who is a big water drinker, monopolizing the bottle and leaving cagemates to wait in line for their turn.

Supplement The Hydration

In addition to fresh water in the water bottle, treats like cucumber, seedless watermelon, cantaloupe, or honeydew melon can provide additional hydration. Cucumber is particularly good because it isn't sweet. Some guinea pigs just don't drink a lot by nature, and enticing them with juicy fruits and vegetables ensures that some extra fluids are getting in their systems. Remember, too, that they get water from their regular daily servings of vegetables (e.g., lettuce leaves, sweet bell pepper chunks, grape tomatoes).

Keep The Water Bottle Clean

Clean the water bottle and drinking spout every other day, as buildup in either can make for icky-tasting water that the pigs won't drink. There are brushes specifically designed for cleaning pet water bottles, but I've found that the best brush is an aquarium filter brush, which has a smaller head and a handle that is more easily bendable, letting you work at all angles to get all interior surfaces clean. Everyone that I've turned on to this tip has been consistently amazed by how much cleaner they can get the sides of the water bottle. For cleaning the drinking spout, nothing  cleans better than the humble, inexpensive, and readily available cotton swab dipped in warm water.

If your water bottle has a black rubber ring inside the cover (as opposed to clear rubber), dry it with a light-colored towel. If you see black smudges on the towel, you need to replace the water bottle -- the rubber ring is breaking down, adding a taste to the water that will cause your pigs not to drink. While you wash out the water bottles, this is a good time to wash out your other pets' water bowls (which can get a little slimy in humid weather).

Spot Clean The Cage

To put it bluntly, lots of water means lots of peeing and this extra peeing will increase cage cleaning duty. Check the cage daily, and spot-clean areas of the bedding that have gotten wet during the day. Leaving such wet spots in the cage can lead to skin problems for guinea pigs and odor problems for everyone's noses. Keep extra bedding on hand to accommodate daily spot-cleanings and more frequent bedding changes. During hot spells, you will go through a little more bedding than usual. However, the cost of extra bedding is still cheaper than the vet bills, time spent traveling to and from the vet office, and time spent nursing your guinea pigs if they come down with a skin problem as a result of having to live on wet bedding. You'll also need to swap in clean and dry cozy cups and sacks more frequently, so you'll want some extra laundry detergent on hand for the extra loads of wash.

Summer is a challenge for pet owners, and even moreso when you have aging or ailing pets (of any species) who are less tolerant of heat and humidity. Our efforts are hampered by the fact that actual temperatures often exceed forecasted temps, making us feel like we're playing hazardous guessing games. Regardless of what species pet(s) you have, keeping your animals amply stocked with water, keeping them in cool environments, and knowing what the early warning signs of heat exhaustion or heatstroke are for the different species in your house will go a long way toward keeping your animals healthy and safe.