When using a toaster oven, space heater or other "heavy" appliance you might notice the plug getting hot during use. Overheating can cause the tines or prongs and also the jaws that grasp the tines inside the socket to corrode and worsen the problem. To forestall a fire you will either clean the prongs or replace the plug and/or cord. Well, the same thing can happen to the mounting contacts inside the box housing your electric meter - except that you don't notice this until it's too late.
Local licensed electricians were not employed to install the 15,000 smart meters
for National Grid's two year Worcester Pilot Program, according to one source. Using licensed workers might not be mandatory for the task of changing meters - anymore than one needs to be licensed to simply plug in an appliance in their home. But, independent
contractors might either not have been trained to inspect electrical contacts for corrosion - or take the time to check as they are on piecework. In a hurry, they will remove and then replace the meter while it is UNDER LOAD; while refrigerators, circulators, heaters and everything else are drawing current! Such installation is illegal: It causes sparking, heating & corrosion of contacts during the instant they are not fully engaged!*
Electrician James Dreyer of Westsyde, BC is well aware of the arcing that occurs when
meters are removed or installed while under load. There have been 40 fires in BC Hydro's
territory because of the new meters or the faulty manner in which most were installed.
The newer meters also lack surge arresters. One of 14,000 holdouts against a change out,he was arrested just before Christmas but the charges were dropped - for now. 
The meters in British Columbia are made by Itron®, the same manufacturer of those being used by National Grid here in Worcester.
Fires Caused by Smart Meters (Sensus® 3.3 or 3.2)
During these first years that Smart Meters have been deployed the meters have
caused fires where they have been installed. Fires may have started either by failure
of the meters or by poor electrical connection of a meter to its box or socket. FPL (Florida Power and Light) customers in Dade County/Miami have had fires
resulting from faulty installation of their new meters. "A Federal lawsuit brought by two Florida Power & Light customers against Honeywell International claims that improper installation of smart meters caused them and at least 13,000 other customers to have to make costly repairs at their own expense. The lawsuit alleges that the installers would “strike the old meter with extreme force” to knock it loose. Then they would “strike the smart meter with extreme force to install it in place of the old meter.” Installers did the job that should have taken at least 5 minutes in 90 seconds, according to the suit." That is 13,000 out of 4.5 million
smart meter installations in 35 south Florida counties 2009-2013 allegedly had problems.
There have been similar fires in Tennessee, Ontario and Saskatchewan. Saskatchewan fires involved a model made by Sensus®. 105,000 of these Sensus® meters were ordered by the province to be replaced after eight fires were found to be caused after rains and moisture build up inside them. [202,202a,202b] Only 5400 of the Sensus® 3.3 with remote shut-off had been used in Queen's Park, Ontario and some eleven smaller communities out of over 4.8 million other smart meters in the province and these were to be replaced by March, 2015. Ontario Fire Marshal's office had linked these devices with 13 small fires since 2011.[202c], [202d]
Portland (Oregon) General Electric (PGE) was to have replaced 70,000 Sensus® meters in late 2014 because of this same risk of catching fire. Many of those had been installed at rental properties in East Multnomah County, OR.  Over 10,000 Sensus® meters were to be replaced in Lakeland, FL. by December, 2014 for the same reason. [204,204a]
Pennsylvania Electric (PECO) had replaced 186,000 Sensus® meters in August, 2012 because of their involvement in several house fires there - two of them serious. The company replaced them with safer units made by Landis & Gyr AG  and completed installation of 1.7 million of these Swiss made meters in December, 2015. But note that Landis & Gyr® meters used by SMUD in California have also been responsible for fires despite having temperature sensing and reporting capability. [205a]
Fires caused by Itron® Meters
Journeyman electrician Bobby Reed, who installed a meter for Oncor [in Texas] that was later involved in a fire, stated to the National Labor Relations Board that Itron® meters do not fit into the meter base, leaving gaps because the blades are thinner than those on the analog meters.  These gaps promote arcing that causes fires. The meter base was designed and certified to hold an analog, and has not been certified by either CSA or UL to hold anything else, especially an electronic meter.
Oncor's Senior director of measurement services observed, "...analog meters did not have the same problem of burning as smart meters." Also smart meters had thinner blades than those of the previous analogs causing their connections to be loose and cause arcing and heating up their connections in the jaws of their bases.  A 30 minute video points to four problems: Installers ruin socket bases; Installing Under Load; Thinner Blades; and Remote Disconnect by the utility are all conducive to arcing. 
Smart Meters have exploded or burned up under surge conditions because they lack a high voltage flashover bypass to ground present on older, analog meters. 5000 meters in Stockton, CA.  where 5000 meters blew off houses and many appliances were damaged after an electrical surge in March, 2015 and 100 more in Capitola, CA. [212a]
also succumbed to high voltage surges in June, 2015 ... despite Capitola having been one of 15 local governments in California to pass an ordinance banning the meters back in 2010. Two California fire captains have reported overvoltage conditions in their own homes they attribute to the changeover to smart meters. They experienced brighter lights and motors speeding up randomly and suddenly. 
Fires being caused by overheating meters are an international problem. Properties in
the US, Canada and Australia have been damaged by catastrophic failure of these newer solid state meters. Such occurrences were relatively unheard of with conventional meters yet in a 2006 article uncovered by SkyVision Solutions a now-retired vice-president of National Grid who knew even back then of the possibility of catastrophic failure in the newer meters said the devices are worth the risk.
Utilities Remove Burned Meters from Fire Scenes
On being summoned to a fire to cut power to a building, a utility's standard practice is to pull the meter rather than deploy a bucket for overhead lines or else put a man down a manhole in the street. But what if the meter itself is burned up? Utilities in jurisdictions
elsewhere often remove the meter (their property) and sometimes the box as well (that belongs to the property owner) regardless if the Fire Marshall has yet ruled out the meter as the cause of the fire. Such "routine practice" should be seen as tampering with evidence or removing a smoking gun.
That practice is not only problematic for fire officials but also for insurance adjusters who might not visit the fire scene until two days later. California insurance adjuster Norm Lambe
wrote about this disturbing trend develop where, on arrival at a fire, the department calls utilities in to disconnect service(s) to avoid spreading the fire. The easiest way to cut electric power is to pull the meter but the utility does this - regardless if it is burned - and sometimes takes the customer's box or meter enclosure with it, claiming "it's ours". When the insurance adjuster comes these pieces of evidence have been removed. 
Smart Meters installed by Nevada Energy in Reno have not been UL certified.
UL limits insertion force to 100 lbs. per square inch to insure workers will have adequate strength to apply 100 lbs. of controlled force installing each meter over the course of the entire work day. If not, a worker may use unauthorized techniques, such as inserting a foreign object in the socket to overextend the Meter jaw or else strike the meter into place.
UL recommends only a vertical rocking motion or else direct pressure be used for meter installation, otherwise the incorrect methods of installation could develop into a hot socket and bring on a fire. 
While past design flaws in smart meter units have been known to cause serious fire hazards and spotty performance, it may be of some comfort to know that the Landis & Gyr® smart meters replacing the more fire-prone Sensus® units in Pennsylvania have temperature alarms that alert the utility if a hot socket or other overheating occurs.  The effectiveness of Landis & Gyr's sensing and reporting technology is still questionable as at least one fire reported on EMF Safety Network involved an L&G unit that did not report an overheated state to the utility before the customer experienced partial power outages and smoke and reported it.
A voluntary standard has been established for new smart meters concerning the composition of their components, resistance of materials to fire, spacing of parts to prevent shorting, protection of batteries to reduce likelihood of combustion, ruggedness of meters, resistance of meter enclosures to fire and to the outside environment, etc.  It remains to be seen if these measures will be adequate going into the future but regardless of promised improvements, the track record of damage from meter fires is prompting insurance companies to reconsider covering such losses. "It appears that as the Smart Meters age, more problems are developing with them. When you couple this with the continued lack of cooperation from the Utility Companies, a reduction in the amount of coverage for an insurance policy is the only remaining answer." 
The EMF Safety Network of California has compiled many more incidents of smart meter fires into 40 pages of news stories and reports sent in from people across the US & Canada. Many occurrences with 'incendiary' photos are documented here:
A recent string of fires and a death on the West Coast that were likely caused by smart meters have raised local concerns about the safety of the equipment in Central Massachusetts.MORE
* Avoiding arcing and corrosion is most critical in a meter box as an owner or tenant can't tell if connections are compromised until lights flicker or it's too late! AC Switches are designed to make and break their connections within the 1/120th of a second that the voltage crosses zero as it reverses polarity. Arcing can cause microscopic hot points on a switch's contacts but this is lessened with the use of alternating current, which goes to zero volts 120 times a second. The contacts in DC vehicle switches must have larger contact areas for a given power rating than an equivalent AC switch and be able to make and break contact as fast as possible.
200 Meter installations a fire risk, electrician says Westsyde resident arrested again while resisting meter swap, News Kamloops [BC], January 7, 2016